PV solar panels are not a sustainable energy source

spot5050

Using current PV technology, solar panels are not a sustainable source of energy for the following reason.

There are two types of solar energy system;

Grid-connected
You install solar panels and sell electricity to the national grid when you have a surplus ie. in the summer / daytime, and buy electricity back from the grid when you have a defecit in the winter / nighttime. You are using the national grid as an infinitely-large yet zero-cost battery.

Off-grid
You install solar panels and connect them to a large bank of batteries which are charged up when the panels are producing a surplus.

According to these studies, grid-connected solar systems can produce more energy than they take to build.
- The Energy Intensity of Photovoltaic Systems
- ENVIRONMENTAL IMPACTS OF PV ELECTRICITY GENERATION

However, adding the energy-cost for batteries makes the system energy-negative even in the most favourable climate.

In other words, in order to provide energy, solar PV systems need a national grid. And because national grids are all hydrocarbon based, solar PV systems are not currently a sustainable source of energy.

I wonder if the same is true for wind turbines? Maybe they also need to be grid-connected to be viable.

Spot

hayseed · Coal Joined: Jun 01, 2007 Posts: 9

I am glad to know that information.

I tried to reverse meter a few years ago and the electric provider said I would have to buy a million dollar liability policy. This year at the annual meeting I was told that all that was needed was a standard homeowner's policy. I was also told that my contribution other than the solar panels would have to be a bit of hardware running around $250. I signed up and started talking to electricians. Turns out it will be more like $3,000 in costs for hardware and electrician fees. The hardware is an inverter and 2 breaker panels to stop surges from them and surges to them. I guess I will pursue it. The solar panels and installation will also run in the thousands. After all this it is a miniscule amount of electricity unless I get lots of solar panels up. However, as far as I know, the only batteries for solar are marine batteries, which only last about 5 years and cost $150 per battery.

I would think it would be in the interest of the power companies to install solar panels on any real estate with sunlight so as to offset the costs of building nuclear or coal. Given this year's weather, carbon charges can't come too soon. If that were instituted, the electric companies would be more interested in providing more assistance in their customer's providing on-site areas for solar power. Certainly cheaper than buying land to put solar panels on. At the level of 4 panels at 150 watts, I was told I would be able to run a TV set and a reading lamp. That is the necessity of life in my opinion though a refrigerator and freezer would be nice.

korosten · Tar Sands Joined: Jun 09, 2007 Posts: 54

What about a third option:

3. Install PV without batteries, and use the power as it is available (during the day only)

Would it be sustainable then?

sicophiliac

Well if you read into the first article they talk about newer thinner film solar cells requiring much less energy to manufacture and thus a much shorter energy payback time. Also solar thermal is another option which I suspect has a good EROEI. I found an article that estimated it at like 27:1 or so and I will try to dig it up again and post a link here soon.

yesplease · Fission Joined: Oct 03, 2006 Posts: 2570

Do you have an LCA for the different batteries?
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vtsnowedin · Intermediate Crude Joined: Jul 11, 2008 Posts: 633

Kerosten hits it on the head. People who live off grid with solar or wind power learn to use it when it is available. You do the laundry when the sun is shining and you only use the toaster if the wind is blowing, hard. The batteries give the convenience of having some power anytime but it is not a necessity and the cost of batteries should be kept separate from the cost of power production. Using the power as it is made lets you skip the losses incured when you run it through the battery charger and back out.

That study was interesting but it assumes that the power to make the panels will be fossil based even though they mention that you could have solar breeding and use existing solar panels to supply the power to make new ones. They never consider that hydro power or nuclear could be used thereby leaving no carbon footprint. As much of the aluminum produced in north America is produced in Canada using their abundant hydropower a significant portion of each panel is already fossil fuel free.
The facts that you can make solar panels using power generated from solar panels and there is a positive rate of return over the lifetime of the panel and that batteries are not a necessary part of an energy system means that the premis put forth by this post is false.

aahala2 · Tar Sands Joined: Mar 25, 2008 Posts: 89

WisJim

PV and wind may not be "sustainable", but certainly are more sustainable than coal, oil or nuclear fueled power sources. At least the power source has a much longer time before it reaches its peak.

dunewalker

yesplease · Fission Joined: Oct 03, 2006 Posts: 2570

From what I've gathered it seems that Lithium batteries store three times more energy than they take to produce/transport, so it seems that off-grid systems can be sustainable, just that battery storage significantly extends to energy paback time.
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strider3700

VMarcHart

I'm having a little trouble with the word sustainable. What is sustainable? Do you mean, 24/7 availability, or good for the environment?

Being connected to a major grid of course gives the 24/7 availability, but is that sustainable? Isn't being sustainable to use energy when available instead of stressing the already fragile system?

I see not being connected to a major grid a very sustainable mean of living. It sure has its discomforts, but the unsatiable search for high levels of comfort is what brought us here.

Food for thought.

cephalotus

there have been huge(!) changes in PV manufacturing during the last 8 years.

New silizium facilities can produce "more dirty PV grade" Silizium with only 10% the amount of energy compared to standard Siliium producers (from 2008!).

Just one example.

cephalotus

vtsnowedin · Intermediate Crude Joined: Jul 11, 2008 Posts: 633