Solar PV is now the most cost efective energy source.

[HackedFridgeMagnet]

The air quality of our house is fine, its a fairly modern wood burning stove. Though bringing dirty logs into the house makes a bit of a mess.
We would have to burn the wood anyway as it's an on going bush fire threat.
But I agree solar energy would be far easier and much better for most.

[CatalinaWOW]

Where I am I would have to do nearly as much wood cutting to keep solar working as I would keeping a wood stove going.  Those pesky trees keep growing and generating more and more shade. 

Of course I could build a structure taller than local tree growth and then have really good insolation.  But I haven't found an economical way to make a large area structure that is 20 meters tall and can take the large wind loads associated with large solar arrays.  And like HackedFridgeMagnet I would still end up clearing trees for a variety of reasons including managing fire hazard.

There is no one answer to renewable energy.  It is very site specific.  Sometimes the answer is hydro.  Sometimes solar.  Sometimes wind, though I pity those who live places where wind is a viable stand alone energy source. 

[mtdoc]

I'm a big fan of solar PV. I have my own 4500 watts of PV installed and plan to install more.  BUT - it's just not realistic for most people who live in cold climates with large amounts of rain/snow in the winter to rely solely on PV for all of their heating needs - no matter how inexpensive PV panels have become, how well insulated their home is, how much heat storage/buffer they have,  etc.  There may be a few cold weather climates where there is enough winter sun to make it work provided it's a small, very well insulated home - but those locations are few in number.

All of the people I know who live off grid with PV have some supplementary energy source for heat - either wood stove, wood masonry heater or propane.  Modern wood stoves or masonry heaters are very efficient and do not have any significant impact on indoor air quality. Outdoor air quality can be affected if there is a large density of these in a small area subject to atmospheric inversion conditions but that is not the case in off grid locations.

I also know of no one who lives off grid with PV who does not have some backup source of electricity generation - usually a generator or if they're lucky wind or micro hydro.

[electrodacus]

The air quality of our house is fine, its a fairly modern wood burning stove. Though bringing dirty logs into the house makes a bit of a mess.
We would have to burn the wood anyway as it's an on going bush fire threat.
But I agree solar energy would be far easier and much better for most.

I did considered wood or pellet for my heating but for me is significantly more expensive than solar and on top of that requires much more work. Pelets are cleaner and even cost less here if you want to by the wood but the feeding mechanism is not always great and all that installation is expensive and not that reliable.

[electrodacus]

Where I am I would have to do nearly as much wood cutting to keep solar working as I would keeping a wood stove going.  Those pesky trees keep growing and generating more and more shade. 

Of course I could build a structure taller than local tree growth and then have really good insolation.  But I haven't found an economical way to make a large area structure that is 20 meters tall and can take the large wind loads associated with large solar arrays.  And like HackedFridgeMagnet I would still end up clearing trees for a variety of reasons including managing fire hazard.

There is no one answer to renewable energy.  It is very site specific.  Sometimes the answer is hydro.  Sometimes solar.  Sometimes wind, though I pity those who live places where wind is a viable stand alone energy source.

Yes if you are in a forest is a bit of a problem to find a good spot for solar PV array. If I knew about the cost drop in price of solar PV panels when I designed my house I will have build a sort of A frame house where the south face will have been covered in PV panels and that will have been enough to fully heat the house.
I will have saved some money on cables since now I need the array on the ground somewhere in front of the house.
Not many people have access to hydro but that is of course a good option in those particular case. Wind is not a good option. I have good wind resources here and I considered all sorts of wind turbines (even had a small one for a year) and the large inconsistency in wind availability requires larger storage so more cost and the tower for that small 300W wind turbine was more expensive than the turbine plus the cable needs to be thinker and longer than for a similar PV panel.
There are just to many downsides to wind for small scale not sure how things look at large scale.

[electrodacus]

I'm a big fan of solar PV. I have my own 4500 watts of PV installed and plan to install more.  BUT - it's just not realistic for most people who live in cold climates with large amounts of rain/snow in the winter to rely solely on PV for all of their heating needs - no matter how inexpensive PV panels have become, how well insulated their home is, how much heat storage/buffer they have,  etc.  There may be a few cold weather climates where there is enough winter sun to make it work provided it's a small, very well insulated home - but those locations are few in number.

All of the people I know who live off grid with PV have some supplementary energy source for heat - either wood stove, wood masonry heater or propane.  Modern wood stoves or masonry heaters are very efficient and do not have any significant impact on indoor air quality. Outdoor air quality can be affected if there is a large density of these in a small area subject to atmospheric inversion conditions but that is not the case in off grid locations.

I also know of no one who lives off grid with PV who does not have some backup source of electricity generation - usually a generator or if they're lucky wind or micro hydro.

I live in a cold climate since I'm in Saskatchewan Canada so colder than any state in US. Also almost all states in US will have better solar than I have here so if it works for me it will likely work anywhere in US.
I know 99% of people do not use solar PV for 100% of the energy that is why is hard to believe is not only possible but is in most cases the most cost effective method.
The example in the pdf document is for my house at my location and my small 65m2 (~700sqft) can be powered 100% with just a 10kW PV array
And yes a typical house in North America is 3x larger and 3x less well insulated so requires up to 9x more energy if it where in the same climate as mine but that is only important for the area needed for the PV array since cost per unit of energy will still be better for solar PV than wood or propane.
I live for about 4 years here offgrid with solar and I do not have any backup for the electricity part. Heating is still temporary with propane (extremely expensive) but by next winter I hope it will be 100% with solar PV.

[mtdoc]

I live in a cold climate since I'm in Saskatchewan Canada so colder than any state in US. Also almost all states in US will have better solar than I have here so if it works for me it will likely work anywhere in US.

Well, I don't know where you are in Saskatchewan I see now that you're from Regina which is far Southern Saskatechewan. There are several places in the  lower 48  US that have lower average annual temperatures than southern Saskatchewan and some with lower annual temps than central Saskatchewan.  Then of course there is Alaska ...

As far as sunshine goes, there are many, many places in the lower 48 US states with much less sunshine than Saskatchewan.

Just for example, Minnesota (one of the coldest US States) averages 180-200 days with sun  per year compared to Saskatchewan's 300 - 325 days (Regina is 322).

Western Washington state where I live and where the large population centers are , averages only 130 -160 day with sun per year.

And then there's Alaska...

Saskatchewan is  a very sunny place - lucky you.

All the weather data for Canada and the US to back up these facts can be found HERE

I agree with your general premise that cheap PV prices mean that solar PV is very cost effective and can and should be more than it is but your are overselling it, with exaggeration.

[electrodacus]

I live in a cold climate since I'm in Saskatchewan Canada so colder than any state in US. Also almost all states in US will have better solar than I have here so if it works for me it will likely work anywhere in US.

Well, I don't know where you are in Saskatchewan I see now that you're from Regina which is far Southern Saskatechewan. There are several places in the  lower 48  US that have lower average annual temperatures than southern Saskatchewan and some with lower annual temps than central Saskatchewan.  Then of course there is Alaska ...

As far as sunshine goes, there are many, many places in the lower 48 US states with much less sunshine than Saskatchewan.

Just for example, Minnesota (one of the coldest US States) averages 180-200 days with sun  per year compared to Saskatchewan's 300 - 325 days (Regina is 322).

Western Washington state where I live and where the large population centers are , averages only 130 -160 day with sun per year.

And then there's Alaska...

Saskatchewan is  a very sunny place - lucky you.

All the weather data for Canada and the US to back up these facts can be found HERE

I agree with your general premise that cheap PV prices mean that solar PV is very cost effective and can and should be more than it is but your are overselling it, with exaggeration.

Yes I wanted to mention that Alaska is excluded but I was thinking that was obvious so did not mention.

But Minnesota is in a better place from solar and climate point of view than Saskatchewan.
Go here http://pvwatts.nrel.gov/ select Minneapolis use a 10kW PV array at 60 degree tilt and leave all other values at default you will see an annual production of 13297kWh vs 14760kWh for Regina Saskatchewan vs 10309kWh in Seattle
Then look in to details for the worst winter months where you have
Minnesota
824kWh in December
1117kWh in January
1146kWh in February

Regina
897kWh in December
1166kWh in January
1252kWh in February

Seattle WA
338kWh in December
415kWh in January
538kWh in February


Now look at the average temperatures for this two locations for the same winter months

Minnesota https://en.climate-data.org/location/1522/
-7.5C in December
-10.9C in January
-7.4C in February

Regina  https://en.climate-data.org/location/373/
-13.3C in December
-16.7C in January
-13.1C in February

Seattle WA  https://en.climate-data.org/location/593/
+5.1C in December
+4.3C in January
+6.1C in February

So yes if I move my house around Minneapolis or Seattle it will do better than here around Regina Saskatchewan because on the winter temperatures vs amount of solar energy.

If I want to heat the house in Regina Sask at +20C in January I need to put enough energy to maintain a 20C + 16.7C = 36.7C delta where in Seattle you need 20C - 4.3C = 15.7C delta
36.7C / 15.7C = 2.34 less energy to heat the same house at this two different locations.

So yes excluding Alaska US has similar or better conditions than I have in Regina Sask. I can move my house and can heat and power my house with a 10kW PV array in any US state except Alaska.

[mtdoc]

You're cherry picking your locations and months and even then the numbers you post do not fully support your assertions. (Seattle's solar insolation is less than half of yours).

You're the one who stated that your location was colder than any place in the US which is not true - even if you exclude Alaska.  Just for example, from the website you link, Angle Inlet, Minnesota is colder. (Dec -14 C, Jan -18.1 C, Feb -14.5 C).

You're the one who said almost all states have better solar resource than you.  Depending on what you mean by "almost all" that is also not true.

My only point is that you live in a cold but relatively sunny location in a small, very well insulated home and therefore your attempt to provide for all your energy needs with solar PV is not going to be replicable for many people living off grid in the USA.  Yes, or course for many others it will. You're just overselling your assertion is all. 

As I've said, I am a big fan of solar PV and it has become a very cost effective energy source - even the most cost effective in some locations. It's not the complete energy solution for everyone (or maybe even most) who lives off grid though.

[CatalinaWOW]

Where I am I would have to do nearly as much wood cutting to keep solar working as I would keeping a wood stove going.  Those pesky trees keep growing and generating more and more shade. 

Of course I could build a structure taller than local tree growth and then have really good insolation.  But I haven't found an economical way to make a large area structure that is 20 meters tall and can take the large wind loads associated with large solar arrays.  And like HackedFridgeMagnet I would still end up clearing trees for a variety of reasons including managing fire hazard.

There is no one answer to renewable energy.  It is very site specific.  Sometimes the answer is hydro.  Sometimes solar.  Sometimes wind, though I pity those who live places where wind is a viable stand alone energy source.

Yes if you are in a forest is a bit of a problem to find a good spot for solar PV array. If I knew about the cost drop in price of solar PV panels when I designed my house I will have build a sort of A frame house where the south face will have been covered in PV panels and that will have been enough to fully heat the house.
I will have saved some money on cables since now I need the array on the ground somewhere in front of the house.
Not many people have access to hydro but that is of course a good option in those particular case. Wind is not a good option. I have good wind resources here and I considered all sorts of wind turbines (even had a small one for a year) and the large inconsistency in wind availability requires larger storage so more cost and the tower for that small 300W wind turbine was more expensive than the turbine plus the cable needs to be thinker and longer than for a similar PV panel.
There are just to many downsides to wind for small scale not sure how things look at large scale.

You are right.  Wind is rarely the answer as a sole energy source.  But there are places where for all practical purposes the wind blows all the time.  Much more than even windy places like Regina.  Not pleasant places to live at all and generally cloudy also, but if you have to live there wind might work out.

Solar has potential in lots of places.  But even with solar there are limitations.  In my current case I didn't mention the bottom of a valley location, or the poor orientation of the roofs (driven at least partly by local geometry) of the already existing house.  Yes, if you are buying land and building a house intended for solar you can select for these factors, but economics works here also.  Prices for land best suited for solar in a given area will rise.  Often for reasons unrelated to solar.  Hilltop locations which have the most access to solar also tend to be prized view lots in urban areas.

[electrodacus]

You're cherry picking your locations and months and even then the numbers you post do not fully support your assertions. (Seattle's solar insolation is less than half of yours).

You're the one who stated that your location was colder than any place in the US which is not true - even if you exclude Alaska.  Just for example, from the website you link, Angle Inlet, Minnesota is colder. (Dec -14 C, Jan -18.1 C, Feb -14.5 C).

You're the one who said almost all states have better solar resource than you.  Depending on what you mean by "almost all" that is also not true.

My only point is that you live in a cold but relatively sunny location in a small, very well insulated home and therefore your attempt to provide for all your energy needs with solar PV is not going to be replicable for many people living off grid in the USA.  Yes, or course for many others it will. You're just overselling your assertion is all. 

As I've said, I am a big fan of solar PV and it has become a very cost effective energy source - even the most cost effective in some locations. It's not the complete energy solution for everyone (or maybe even most) who lives off grid though.

I did not try to cherry pick a location just took the largest known city in the state you mentioned.
I see that the particular town with a population of 60 people according to google has slightly lower temperatures than my location (not significant) and will require 2 to 3% more energy to heat than at my location.
If you look on the map where that small town is located is basically in Canada and it also has lower solar resources but I can call this cherry picking

I guess most people living offgrid have enough land for a large ground mount PV array. All other energy sources will be way more expensive when you take the entire system in to account.
If you live in a house that already has a natural gas connection and the natural gas furnace then there will be no gain to go with solar PV.
But If you have an offgrid house and you use propane, heating oil or wood/pellets then I will say is extremely likely that PV will be significantly more cost effective especially in cold locations where heating season is a big part of the year.
And this is just the benefit for heating used stand alone but when electricity is also needed the combination of heating and electricity brings even more advantages since it reduces the battery size needed for electricity storage by at least half if not more and makes the offgrid electricity competitive with grid if not better.

The 10kW PV array as mentioned before will produce 14.7MWh in a year at my location and from that I will use around 4000 to 5000kWh for heating depending on winter and in my case just around 1000 to 1200kWh electricity (maybe that will increase in the future but is not relevant there is plenty of excess).
Total cost of the parts including the battery SBMS and inverter that I already have will be around $15k
Assuming a 25 years amortization period where another 1000 to $2000 battery may be needed in the future and a $400 inverter say $17k for 25 years
$17k / 25 years = $680/year = $56.6/month
The PV array that is the main cost of the system will continue to work probably for much more than 25 years so cost amortization will be even lower.
Selecting any other heating option like wood or propane will make the electricity part much more expensive close to 2x the cost mostly because of the higher battery capacity needed.
So while you can split that $57/month in say about $40/month for heating and $17 for electricity the electricity will get to around 30 to $35/month without the oversized PV array used for heating and with the large capacity battery so then your separate heating solution will need to be just $22/month about $264/year in order to be equal with PV heating.

Hope you get the idea related to benefit of combining heating and electricity.
I just do not see any way for any other energy source to compete with PV and PV and Lithium battery prices will only go down while other energy sources will probably stay the same or even go up in price.
And yes there is that disadvantage that you need to pay in advance for all that energy by purchasing the PV panels.

You are right.  Wind is rarely the answer as a sole energy source.  But there are places where for all practical purposes the wind blows all the time.  Much more than even windy places like Regina.  Not pleasant places to live at all and generally cloudy also, but if you have to live there wind might work out.

Solar has potential in lots of places.  But even with solar there are limitations.  In my current case I didn't mention the bottom of a valley location, or the poor orientation of the roofs (driven at least partly by local geometry) of the already existing house.  Yes, if you are buying land and building a house intended for solar you can select for these factors, but economics works here also.  Prices for land best suited for solar in a given area will rise.  Often for reasons unrelated to solar.  Hilltop locations which have the most access to solar also tend to be prized view lots in urban areas.

Yes there may be a few places where wind is more constant and maybe good to consider. I'm a bit biased here since I always prefer solid state devices and dislike any moving parts.
Is unfortunate that you have bad access to solar but from what you say that seems a as a grid connected house and live in some sort of urban area. There is always the possibility to move to a location with better solar access
Most house in urban areas are large and not properly insulated (just minimum by local code) so the surface of the PV array needed to provide 100% of the energy will be high and most likely the space for that will not exist (small lots in urban area).
While solar PV is cheapest it will not work in any place because of this limitations mentioned and probably others.
There is no doubt in my mind that solar PV will probably be the dominant energy source in 10 to 15 years and many things will change with this.

[mtdoc]

I see that the particular town with a population of 60 people according to google has slightly lower temperatures than my location (not significant) and will require 2 to 3% more energy to heat than at my location.
If you look on the map where that small town is located is basically in Canada and it also has lower solar resources but I can call this cherry picking

That's just the first town I saw on the Minnesota page that was colder. The pages were alphabetical and it was a town starting with an A.  I'm sure there are many others. In fact there are several towns in many of the northern US states (and state with high altitudes like Colorado) with temps that are essentially just as cold as yours.

But of course I only had to point out one to disprove your prior statement

It's ok.   I agree that you live in a very cold place and it's impressive what you've done with your energy conservation measures and I have no doubt given the relatively abundant sunshine you have that with enough thermal storage you can get enough PV up to supply all your energy needs.  Just realize that yours in not the worst case scenario.

I guess most people living offgrid have enough land for a large ground mount PV array.

The issue is not acreage.  Many if not most people off grid do not live in the open plains like you do. Trees are a major factor in much of the rural USA.  Local topography - mountains and hills can also limit solar exposure. Even if I cut down all the trees around my home, I would still only have about 4 hours of potential direct sun exposure in the dead of winter due to a mountain ridge to the south of me.

Many people who live off grid live in the forest and/or mountains.

All other energy sources will be way more expensive when you take the entire system in to account.

Again, I think you are overselling it.  Heating with wood is very economical (sometimes almost free) in many locales and in those places PV will never compete on price. With propane prices so low - propane heat is also very cheap and if prices stay low PV will only beat it on price with a very long term amortization.  And yes, in a few select locations wind or microhydro will be cheaper. Using the words "All" and "way more" is hyperbole.

I agree that solar PV energy prices will only get lower and that it will continue to see wider and wider adoption. But it is no Panacea.

[CatalinaWOW]

Is unfortunate that you have bad access to solar but from what you say that seems a as a grid connected house and live in some sort of urban area. There is always the possibility to move to a location with better solar access
Most house in urban areas are large and not properly insulated (just minimum by local code) so the surface of the PV array needed to provide 100% of the energy will be high and most likely the space for that will not exist (small lots in urban area).
While solar PV is cheapest it will not work in any place because of this limitations mentioned and probably others.
There is no doubt in my mind that solar PV will probably be the dominant energy source in 10 to 15 years and many things will change with this.

You are again projecting your assumptions on others.  Yes, my house is grid connected.  Which is fortunate, because it would be quite difficult to work this location off grid.  It is well insulated, and in a milder climate than you have in Saskatchewan, but it is still difficult.  Is it an urban area?  Definitions differ.  According to the zoning it is exclusively agricultural use.  It is 17 miles from the nearest edge of a small (less than 100k people) city.  I am dependent on wells and septic systems for water and sewer and satellite for internet.  I can see neighbors houses (in winter when the deciduous trees have lost their leaves), but it is 150 meters to the street.  The neighbors raise various crops for income.  Most would call it rural.  At best it is exurban.  It is a large enough lot that from an engineering standpoint I could clear trees for an array.  But environmental rules say I can't cut more than six trees without replacing them.  All of my wood cut for burning is replaced with new trees.  Yea sustainability.

My case isn't representative, any more than your location in Saskatchewan is representative, but it is a common situation.  If you look at population censuses, the great plains of North America have some of the lowest population densities on the continent.  Large numbers of people live in exurban, hilly and wooded zones.

I could move to a more favored location for solar, but as I mentioned in the earlier post, that is not a general solution.  Everyone cannot live in favored solar locations.  If many people try, the cost of those locations will rise (and that cost increase should be included in the cost of solar).

I have no doubt that solar will grow in importance.    In most countries it will become one of the major elements of the energy mix.  But until storage becomes a great deal better, or until some really huge investments in infrastructure (house insulation, distribution and other things) are made it will not be dominant.  I don't see that happening in just twenty years.  That is consistent with your own dismissive observations about the current urban infrastructure (where most energy is used).  Until all those houses are rebuilt with better insulation and lower energy needs and support for the most possible solar installation they will be dependent on bulk energy sources.  Some of which will be solar, but even that will require massive investments.  Those investments will occur as current investments wear out, or when the ongoing economic differential grows so large that it justifies losing existing investments.  Solar isn't that good yet.

[electrodacus]

You are again projecting your assumptions on others.  Yes, my house is grid connected.  Which is fortunate, because it would be quite difficult to work this location off grid.  It is well insulated, and in a milder climate than you have in Saskatchewan, but it is still difficult.  Is it an urban area?  Definitions differ.  According to the zoning it is exclusively agricultural use.  It is 17 miles from the nearest edge of a small (less than 100k people) city.  I am dependent on wells and septic systems for water and sewer and satellite for internet.  I can see neighbors houses (in winter when the deciduous trees have lost their leaves), but it is 150 meters to the street.  The neighbors raise various crops for income.  Most would call it rural.  At best it is exurban.  It is a large enough lot that from an engineering standpoint I could clear trees for an array.  But environmental rules say I can't cut more than six trees without replacing them.  All of my wood cut for burning is replaced with new trees.  Yea sustainability.

My case isn't representative, any more than your location in Saskatchewan is representative, but it is a common situation.  If you look at population censuses, the great plains of North America have some of the lowest population densities on the continent.  Large numbers of people live in exurban, hilly and wooded zones.

I could move to a more favored location for solar, but as I mentioned in the earlier post, that is not a general solution.  Everyone cannot live in favored solar locations.  If many people try, the cost of those locations will rise (and that cost increase should be included in the cost of solar).

It seems that you have quite a bit of land is just that is all forest.  Most of the US surface is not covered by forest and also large surface is not populated so I do not think land will ever be a problem.
And I agree that most people all over the globe live in urban areas where my solution may not work especially since most houses have bad thermal insulation and need large quantities of energy for heating thus requiring large PV arrays.
US is extremely fortunate in therms of solar especially when compared to most European countries. 

I have no doubt that solar will grow in importance.    In most countries it will become one of the major elements of the energy mix.  But until storage becomes a great deal better, or until some really huge investments in infrastructure (house insulation, distribution and other things) are made it will not be dominant.  I don't see that happening in just twenty years.  That is consistent with your own dismissive observations about the current urban infrastructure (where most energy is used).  Until all those houses are rebuilt with better insulation and lower energy needs and support for the most possible solar installation they will be dependent on bulk energy sources.  Some of which will be solar, but even that will require massive investments.  Those investments will occur as current investments wear out, or when the ongoing economic differential grows so large that it justifies losing existing investments.  Solar isn't that good yet.

I think thermal storage is the best solar energy solution and I hope this will be adopted more. People up to now mostly where using PV solar for electricity needs not heating.
As seen in the IEA document most of the house energy is used for heating and hot water and there thermal storage makes the most sense since is extremely inexpensive and I do not think electrochemical battery will ever be able to compete with thermal storage.
When searching for an energy source to power my house I looked at all available options and my main criteria of selection was low cost.
Solar installations around the globe has an exponential growth for the past  10 to 15 years with doubling installed capacity almost each two years.
Solar PV already exceeded 1% of total energy needs back in 2015 https://cleantechnica.com/2015/06/12/solar-power-passes-1-global-threshold/
If the trend continues all is needed are 6 or 7 doubling to get to 100% that is around 15 years if trend continues with doubling installed capacity each 2 years.
Yes the trend will slow down probably that is why I mentioned over 50% of the electricity provided by solar in 10 to 15 year.

Again, I think you are overselling it.  Heating with wood is very economical (sometimes almost free) in many locales and in those places PV will never compete on price. With propane prices so low - propane heat is also very cheap and if prices stay low PV will only beat it on price with a very long term amortization.  And yes, in a few select locations wind or microhydro will be cheaper. Using the words "All" and "way more" is hyperbole.

I agree that solar PV energy prices will only get lower and that it will continue to see wider and wider adoption. But it is no Panacea.

I disagree that heating with wood is more economical than both PV heating and natural gas (where that is available and at the current price).
Cost amortization for my particular cost is as mentioned before $264/year for the heating part so try to imagine how will that be competitive with wood where you need to amortize the EPA rated stove and all the work needed o collect the wood cutting and storing.
My house will need about one cord of wood (4000lb) ~ 2000kg for per year assuming a good 70% efficient EPA rated stove.
If I where to buy that wood here it will cost a bit more than $264 (cost amortization of PV solar heating) and that is just the wood no storage space and stove amortization cost plus time spent and maintenance. 

[mtdoc]

Again, I think you are overselling it.  Heating with wood is very economical (sometimes almost free) in many locales and in those places PV will never compete on price. With propane prices so low - propane heat is also very cheap and if prices stay low PV will only beat it on price with a very long term amortization.  And yes, in a few select locations wind or microhydro will be cheaper. Using the words "All" and "way more" is hyperbole.

I agree that solar PV energy prices will only get lower and that it will continue to see wider and wider adoption. But it is no Panacea.

I disagree that heating with wood is more economical than both PV heating and natural gas (where that is available and at the current price).
Cost amortization for my particular cost is as mentioned before $264/year for the heating part so try to imagine how will that be competitive with wood where you need to amortize the EPA rated stove and all the work needed o collect the wood cutting and storing.
My house will need about one cord of wood (4000lb) ~ 2000kg for per year assuming a good 70% efficient EPA rated stove.
If I where to buy that wood here it will cost a bit more than $264 (cost amortization of PV solar heating) and that is just the wood no storage space and stove amortization cost plus time spent and maintenance.

You're generalizing your situation to others. A cut and split cord of wood costs $200 delivered here.  But the people I know who live off grid (and others)often get a free ($20 some juristictions) permit which allows them to cut 4-6 cords of wood a year on state or national forest land.  Others have enough wood on their property.   Storage of wood is free for most people - they already have woodshed/tarps/porch etc.

Also, in addition to the cost of extra PV panels, are you including the cost of more battery and/or thermal storage?  How about the cost of extra charge controller, wire, combiner box, etc to deal with the additional PV input?  What about the cost of mounting the panels?  Those things also have maintenance and eventual replacement costs.

Just because something makes economic sense for your situation does not mean it will apply to others.

[electrodacus]

You're generalizing your situation to others. A cut cord of wood costs $200 delivered here.  But the people I know who live off grid (and others) buy a $20 permit which allows them to cut 4 cords of wood on national forest land.  Others have enough wood on their property so they only have to pay for a bit of chainsaw fuel and maintenance.  Storage of wood is free for most people - they already have woodshed/tarps/porch etc.

Also, in addition to the cost of extra PV panels, are you including the cost of more battery and/or thermal storage?  How about the cost of extra charge controller, wire, combiner box, etc to deal with the additional PV input?  What about the cost of mounting the panels?  Those things also have maintenance and eventual replacement costs.

Just because something makes economic sense for your situation does not mean it will apply to others.

$200 for a cord is good (better than here for sure) but still that is not all as mentioned and the $20 for permit is also fine but you need to work to get that wood cut and transported. The stove can also be a significant cost and needs maintenance and replacements.
My calculation includes all parts needed PV, cables, battery, thermal storage, controllers, heating cables,LiFePO4  battery .... as you can see in more details in my presentation. Also the replacement battery and inverter was included in the cost as mentioned in one of the above posts.
No extra charge controller is needed the DMPPT450 and SBMS120 are designed for a minimum 25 years life and they do not contain any parts that degrade (there are no electrolytic capacitors used). Also the cost is realy low for those and represent a very small percentage of the total cost (usually less than 5%)
And yes you are right about me not including the installation cost since I will be doing that. But that time is once in the beginning no other work needed for the next 25 years and there should be no maintenance other than replacing the battery once every 10 years or so and eventually the inverter none of this two are related to the heating part since the heating needs no LiFePO4 battery or inverter.
The heating part is made out of only PV panels, cables, DMPPT450, heating cables and thermal mass none of this have any maintenance or replacement needed for more than 25 years (can be 50 years).
PV panels will degrade maybe at a rate of less than 0.5% per year (my first panels have already more than 5 years and I can not realy say if there is a degradation in output it will be difficult to measure).

[cmhansen]

A cut and split cord of wood costs $200 delivered here.

I'm going to go 'out on a limb' and say that's pine and not oak.  The time you don't spend chopping or feeding any wood for that matter will be spent cleaning up ashes.  And, firewood is never going to be as dry as you want it.

You can use 100% solar even in Alaska, the panels just need to be on a HVDC line a couple thousand miles south or so, say a solar plant in sunny SK.  Keep the battery local.  Plus for EVs anywhere, some centralized generation is needed to charge on the go, or even at home really.  I suppose you could get 100kWh out of a 20kW array if you have a very sunny day, but that's a whole day's worth for just one car.

[mtdoc]

A cut and split cord of wood costs $200 delivered here.

I'm going to go 'out on a limb' and say that's pine and not oak.  The time you don't spend chopping or feeding any wood for that matter will be spent cleaning up ashes.  And, firewood is never going to be as dry as you want it.

No pine here. All Doug Fir, Alder, Hemlock, and some maple. When I lived in Vermont $200 would get you a cord of good Eastern hardwood. Exceptional heat content.

Ashes and dry wood is no issue at all. Our stove burns so efficiently, I only need to shovel out ashes every 2 cords or so. That takes about 2 minutes tops. Dry wood is easy. Use seasoned wood, cut, properly stacked and covered. No biggie.

I suppose it seems like a big deal to someone with no experience heating with wood but it's like any other regular household task - washing dishes, clothes, sweeping floors, watering the garden - or clearing snow off the solar panels and maintaining the battery bank...

[electrodacus]

You can use 100% solar even in Alaska, the panels just need to be on a HVDC line a couple thousand miles south or so, say a solar plant in sunny SK.  Keep the battery local.  Plus for EVs anywhere, some centralized generation is needed to charge on the go, or even at home really.  I suppose you could get 100kWh out of a 20kW array if you have a very sunny day, but that's a whole day's worth for just one car.

Alaska has better solar resources than Germany so solar PV is not realy a problem there.
Yes cars need a lot of energy and I do not have any good solution for that. A car is usually not at home during the day and charging an EV battery from another battery is a realy bad idea in therms of cost amortization.
In fact as of now battery cost amortization on EV is so high that makes them more expensive to drive than gasoline cars.
I do not drive much and for now I will stay with my gasoline car and I hope that in near future the self driving cars (level 5 autonomy) will make owning a car obsolete and ordering a car at any time more convenient and cost effective at least for me since I do not need to drive much.
With the 10kW PV array in SK I have an annual average generation of 42kWh/day with some particularly good sunny days in spring exceeding 70kWh/day
My driving needs are low about once a week a 150km drive that is around 38kWh (less in summer depending on EV) or about 152kWh/month and I can probably get that easy from the 10kW PV array if needed (a bit harder in the 3 winter months but no problem in the other 9 months).

[mtdoc]

I have a Chevy Volt and rarely use any gas in it ( i rarely drive more than 30 miles in a day). Its cost to operate is way less tban our gas cars. In the summer i can charge it with excess PV production. 12 kWh gets me 30-40 miles.  Battery amortization is a non issue. The new purchase price was no more than a similiarly equiped gas only car. Maintenance costs are much less since oil and brake costs are minimal. Battery replacement in 10-15 years will cost no more than what ICE tune ups, timing belt replacements, oil changes, etc would have cost.

We will be replacing my wifes's Volvo with a Chrysler Pacifica PHEV this spring.

Some parts of Alaska have good solar insolation in the summer months but forget about it in the winter. In northern Alaska there is few hours of potential sun (or none!). Even in the south were there is a few more hours of sun potential it is often cloudy. Try looking at PV Watts data for SE Alaska in the winter.....

[electrodacus]

I have a Chevy Volt and rarely use any gas in it ( i rarely drive more than 30 miles in a day). Its cost to operate is way less tban our gas cars. In the summer i can charge it with excess PV production. 12 kWh gets me 30-40 miles.  Battery amortization is a non issue. The new purchase price was no more than a similiarly equiped gas only car. Maintenance costs are much less since oil and brake costs are minimal. Battery replacement in 10-15 years will cost no more than what ICE tune ups, timing belt replacements, oil changes, etc would have cost.

We will be replacing my wifes's Volvo with a Chrysler Pacifica PHEV this spring.

Some parts of Alaska have good solar insolation in the summer months but forget about it in the winter. In northern Alaska there is few hours of potential sun (or none!). Even in the south were there is a few more hours of sun potential it is often cloudy. Try looking at PV Watts data for SE Alaska in the winter.....

I'm not very familiar with Chevy Volt but it seems it has a starting msrp of $33k vs a malibu starting msrp $22k so I think there is a premium that you pay for the battery and electric motor.
Trying to amortize that will be impossible with the current gasoline price.
In any case an EV will need a battery for energy storage while the gas tank on ICE is almost free. Cost amortization for that battery (with current prices of those batteries) will make an EV more expensive to drive.

A 10kW array 60 degree tilt in Berlin will only produce 8348kWh in a year while same in Anchorage Alaska 9013kWh while winter months production are almost the same.

[mtdoc]

I'm not very familiar with Chevy Volt but it seems it has a starting msrp of $33k vs a malibu starting msrp $22k so I think there is a premium that you pay for the battery and electric motor.

1- The Volt is a completely different class of car than a Malibu.  Perhaps comparing the full EV Chevy Spark would be comparable - it's MSRP starts at 25K  but after tax rebate it would be $17.5K

2- I paid 32.5 K for my Volt out the door and it has the premium (leather) trim and back up camera.  After $7.5 K tax rebate it cost me 25K.

An equivalent ICE car would cost more so there is nothing to amortize. As I pointed out given the lower operating costs it's a no brainer.

while winter months production are almost the same.

   Winter production is not even close to summer!!!.  How could it be given how short the days are in the winter?   (add:) Maybe you meant compared to Berlin? -Irrelevant to me - and not part of my prior post - I was stating the fact that winter production in AK is very poor. Here's the data from PV watts   As you can seen the winter months production is between 1/8th and 1/3rd of summer.  Barely enough to keep lights and  a refrigerator on. And that is assuming you keep the panels free of snow at all times.

[electrodacus]

I'm not very familiar with Chevy Volt but it seems it has a starting msrp of $33k vs a malibu starting msrp $22k so I think there is a premium that you pay for the battery and electric motor.

1- The Volt is a completely different class of car than a Malibu.  Perhaps comparing the full EV Chevy Spark would be comparable - it's MSRP starts at 25K  but after tax rebate it would be $17.5K

2- I paid 32.5 K for my Volt out the door and it has the premium (leather) trim and back up camera.  After $7.5 K tax rebate it cost me 25K.

An equivalent ICE car would cost more so there is nothing to amortize. As I pointed out given the lower operating costs it's a no brainer.

Like I mentioned I'm not an expert in cars but I think that Malibu was equivalent since seems the same class of car from same manufacturer and just the 1.5liter ICE so without the battery and electric motor on the Volt.
Just made a quick search and it seems a better comparison will be Chevrolet Cruze at $19656 and you can read here about operating cost and payback https://en.wikipedia.org/wiki/Chevrolet_Volt

  Winter production is not even close!!!.  How could it be given how short the days are in the winter?  Surely as an engineer your understand this..     Here's the data from PV watts   As you can seen the winter months production is between 1/8th and 1/3rd of summer.  Barely enough to keep lights and  a refrigerator on.

Winter months in Anchorage have the same amount of solar as in Berlin Germany and that is what I was saying with this: "A 10kW array 60 degree tilt in Berlin will only produce 8348kWh in a year while same in Anchorage Alaska 9013kWh while winter months production are almost the same."

[mtdoc]

Winter months in Anchorage have the same amount of solar as in Berlin Germany and that is what I was saying with this: "A 10kW array 60 degree tilt in Berlin will only produce 8348kWh in a year while same in Anchorage Alaska 9013kWh while winter months production are almost the same."

OK - yeah - I read you post initially as claiming winter months was the same as summer - since that was my earlier point (nothing in my post about Berlin). Once I realized my error I edited my post but too late!

The comparison to Berlin is irrelevant to me and was not part of my prior posts. My point has continued to be that winter PV production is very low in AK and many other places - making any reasonable sized array insufficient to supply all one's energy needs in winter. Farther south - in the mid northern latitudes - such as were you live it could work- but even then only in the most extreme cases - i.e. very small, very will insulated home with lots of thermal storage - in a location with relatively good solar insolation.

[electrodacus]

Winter months in Anchorage have the same amount of solar as in Berlin Germany and that is what I was saying with this: "A 10kW array 60 degree tilt in Berlin will only produce 8348kWh in a year while same in Anchorage Alaska 9013kWh while winter months production are almost the same."

OK - yeah - I read you post initially as claiming winter months was the same as summer - since that was my earlier point (nothing in my post about Berlin). Once I realized my error I edited my post but too late!

The comparison to Berlin is irrelevant to me and was not part of my prior posts. My point has continued to be that winter PV production is very low in AK and many other places - making any reasonable sized array insufficient to supply all one's energy needs in winter. Farther south - in the mid northern latitudes - such as were you live it could work- but even then only in the most extreme cases - i.e. very small, very will insulated home with lots of thermal storage - in a location with relatively good solar insolation.

I will not recommend someone in Anchorage Alaska to do solar PV heating unless the other energy sources are quite expensive. It is warmer there than at my location but still colder than Berlin Germany so it will depend on the prices of other energy sources like Natural Gas.
In Germany is not as cold and the cost of other energy sources is high enough that a PV heating will make economic sense but a lot of space will be needed depending on house size and energy needs.
There are houses there (in Germany) with better thermal insulation than mine so much so that even the heat from the appliances can keep the house warm.