Electronics > Power/Renewable Energy/EV's
Solar PV is now the most cost efective energy source.
electrodacus:
While hard to believe Solar is the most cost effective energy source at least for individual use not sure about large scale production.
I live in a cold but relatively sunny climate and after evaluating all energy sources for my offgrid house I decided that I will be using solar PV energy to heat my house.
Currently I use propane that is an order of magnitude more expensive about 25 cent/kWh vs just 2.4cent/kWh for PV panels.
Most people in the world use a mix of grid electricity and natural gas for house energy needs where natural gas is significantly less expensive than electricity (at least 4 to 5x) per unit of energy so house heating and hot water that is usually more than half of a typical house energy needs is delivered by natural gas.
Heating with solar PV panels can be extremely simple. Just connect a long wire with appropriate resistance to the PV panel output and you just made a completely solid state heater. You can drop that cable in water and you made a water heater. Problem with this simple approach is that is not very efficient best case 80% efficient in a clear sunny day with perfectly calculated resistive element and can be lower than 20% efficient in a completely overcast day.
That is why I came up with a simple but effective solution called Digital MPPT thermal controller (no expensive and unreliable DC-DC converters involved).
If you are curios on how Digital MPPT thermal controller works you can read my presentation about that here http://electrodacus.com/DMPPT450/dmppt-presentation-v01.pdf it is Open Source so there are no secrets all is explained and I think is educational even if you are not interested in the Digital MPPT thermal controller.
Yes the DMPPT450 will be on Kickstarter together with new version of SBMS but what I'm most interested in is your opinion about the Solar PV heating (cooling also possible using peltier elements but I need no cooling at my location in Canada and even where cooling is needed it represents a much smaller percentage of the total house energy use so is less important).
:palm: Below there is a long discussion regarding heat pumps and their COP (Coefficient of performance) when cascaded (two stage) please ignore all since I was wrong about the COP o such a system and if you want the correct answer you can see first post in page 3.
TechnicalBen:
Are you considering lifespan costs?
I've only done back of the napkin stuff myself for "pie in the sky" imaginary projects. But I was getting the same cost as a small gas/petrol/diesel heater but a more elegant solution to burning stuff. Batteries were the biggest possible cost, so other forms of storage (heat sinks underground etc) could work out better. But I did read up that Solar uses more carbon in production than it saves in use... and can at times miss energy or economic returns too.
But it is entirely dependent on the sale and install price, along with the expected lifespan. And the stuff I've read relates to industrial/national production not small scale home use...
djacobow:
At the utility scale, in places with good solar resource, PV can indeed be cheaper than prevailing sources (gas combined cycle, coal) on a /kWh basis. PV advocates call this "grid parity" -- and it is a real thing. PV is usually not cheaper than wind in windy places, but many places are not suitable for that.
However, you cannot run a power system from PV alone (the sun is intermittent, not dispatchable, and doesn't shine at night), so the /kWh basis is not quite the right way to think about.
Furthermore, there is an interesting phenomenon in places with lots of PV penetration, where the existence of the PV actually makes the output from the gas plant _appear_ more expensive on a /kWh basis. It happens when the owners of a gas- or coal-powered resource needs to recoup the cost of the plant over smaller and smaller kWh sales, because that utility is getting more energy from PV and wind. What's interesting in this case is that the gas or coal plant is still needed (because of flexibility) but much less energy is needed from it.
As for residential solar for heating, why not just heat your storage medium / working fluid directly? Why go through the electrical step? It will make substantially more efficient use of the sunlight. The technology for this has existed for a very long time.
electrodacus:
--- Quote from: TechnicalBen on January 09, 2017, 11:54:15 pm ---Are you considering lifespan costs?
I've only done back of the napkin stuff myself for "pie in the sky" imaginary projects. But I was getting the same cost as a small gas/petrol/diesel heater but a more elegant solution to burning stuff. Batteries were the biggest possible cost, so other forms of storage (heat sinks underground etc) could work out better. But I did read up that Solar uses more carbon in production than it saves in use... and can at times miss energy or economic returns too.
But it is entirely dependent on the sale and install price, along with the expected lifespan. And the stuff I've read relates to industrial/national production not small scale home use...
--- End quote ---
I use cost amortization for comparison as you probably seen in the pdf document.
As a simple example PV panels cost amortization is 2.4 cent/kWh (USD) (based on 80 cent/Watt acquisition cost, 25 year amortization period and amount of solar at my location).
petrol for example is now here about 70cent/liter and one liter contains about 9.5kWh of energy/liter so cost is 7.4 cent/KWh significantly higher than PV cost amortization.
This is not all a Gasoline (petrol) burner will not be 100% efficient and be more complex less reliable compared to a simple resistive heat element needed for PV heating and that will make a heater based on petrol significantly more expensive when all that is considered burner, pipes, heat exchanger maybe pumps....
Natural gas is for sure the cheapest form of fossil fuel and that is why I used that in my comparison showing that even that can not compete with direct PV heating and thermal mass storage.
Is extremely wrong to say solar PV panels require more energy to produce than they generate over their life. If that will be true the cost of PV panels will be much higher than it is since you need to pay for that energy when you buy the panel.
The amount of energy used to produce a PV panel can be produced by the panels in just 2 to 4 months. So yes you can build a profitable PV panel factory powered with PV solar energy.
--- Quote from: djacobow on January 10, 2017, 12:39:06 am ---At the utility scale, in places with good solar resource, PV can indeed be cheaper than prevailing sources (gas combined cycle, coal) on a /kWh basis. PV advocates call this "grid parity" -- and it is a real thing. PV is usually not cheaper than wind in windy places, but many places are not suitable for that.
However, you cannot run a power system from PV alone (the sun is intermittent, not dispatchable, and doesn't shine at night), so the /kWh basis is not quite the right way to think about.
Furthermore, there is an interesting phenomenon in places with lots of PV penetration, where the existence of the PV actually makes the output from the gas plant _appear_ more expensive on a /kWh basis. It happens when the owners of a gas- or coal-powered resource needs to recoup the cost of the plant over smaller and smaller kWh sales, because that utility is getting more energy from PV and wind. What's interesting in this case is that the gas or coal plant is still needed (because of flexibility) but much less energy is needed from it.
As for residential solar for heating, why not just heat your storage medium / working fluid directly? Why go through the electrical step? It will make substantially more efficient use of the sunlight. The technology for this has existed for a very long time.
--- End quote ---
Wind in the end is still solar energy but for small scale even in windy locations like mine are not cost effective when compared to solar PV and they are more intermittent requiring a larger storage capacity.
If you check the document the thing that makes the DMPPT450 cost effective and possible is the combination of cheap PV panels with cheap thermal mass energy storage below 0.5cent/kWh to store energy in thermal mass.
The large thermal mass and large size PV array to provide the house with heating also helps reduce the Lithium battery storage to at least half thus helping also reduce the cost of electrical energy needed for appliances in the house.
I will need no backup energy source for my house and the DMPPT450 + SBMS + PV panels + large thermal storage + small LiFePO4 battery can make a house completely energy independent or a Net Zero energy house at a cost lower than traditional grid electricity + natural gas. For a new house difference is even higher because of the connection cost to those utilities.
The thermal solar was also used in my comparison and that is less cost effective than PV solar heating and less reliable. See page 5 for comparison table.
TechnicalBen:
Yep, sorry, it was the carbon costs that may never balance out, not the electric production (with exception of really small badly made useless stuff :P ).
Navigation
[0] Message Index
[#] Next page
Go to full version