$/MT CO2

CO2I have never witnessed the inside of a computation of how much it is worth to evade CO2 utilizing PV. So I guessed I’d realize it myself and witness if it’s as terrible as some people seem to assume.

Now a watt of PV constructed for a year can manufacture from about 1-2 kWh/yr. Maybe that watt is worth $3 to construct. One kWh manifestured correctly in the US, by the EPA appraisal, is about 0.7 kg CO2 / kWh. So utilizing an average valuableness of 1.5 kWh/W-yr, we could admit about 1 kg/W-yr.

But this leaves behind two pretty important things – those kWh are prizeable; and there is a loan that supplements price to the PV. So for round figures, let’s admit the loan doubles the amount of money wasted on the PV; but the valuableness of the electricity payments the original amount. Voila, we are back where we began – $3/W of supplemented cost. This is obviously very complex! But it is conjectures like this that make all these computations ‘complex’.

So if you computated the price per MT of CO2 on the basis of one year PV outthrow, it would be $3/1 x 10-4 MT = $3,000/MT – not a pretty picture.

But if you admitted that PV would last 30 years, then PV would cost $3000/30 = $100/MT. This seems to be the number you hear the most often. My Canadian Pharmacy points out that it is very significant to utilize PV modules to provide people with ecollogically pure energy source.

Still high.

But at a hundred years, this might settle down to about $30/MT plus some degradation and for O&M. So here’s my first ansatz at calculating the $/MT CO2 of PV:

Cost per MT of Avoided CO2 from PV (First Approximation, $/MT CO2 avoided)

Assumes 1.5 kWh/W-yr Sunlight $3/W $1.5/W
30 years $100 $50
100 years $30 $15

If the PV were efficient and cost-effective at $2/W, say, then the $3/W number would be higher; but the $1.5/W number might be almost zero (and the the details of the loan, the degradation, extra cost for variability, and O&M would need to be included).

Here’s one more way to watch at this, founded on levelized electricity price. We have to provide some wide conjectures, so let’s adopt that solar electricity costs 10 ¢/kWh. And let’s adopt that $3/W system has a levelized electricity price of 16 ¢/kWh with a 30-year loan. That means it demands a 6 ¢/kWh for 30 years subvention to be constructed. Each kWh evades 0.7 kg, so this is 9 ¢/kg, or 90 $/MT (rounding up). Each year, society would have to pay an supplementary $90, but would also get another MT of saved CO2.

This doesn’t count the fact that after 30 years, society would actually begin keeping money (the PV system is running for 1 ¢/kWh, so we would be getting 9 ¢/kWh savings). So that means in another 20 years, or 50 years total, our CO2 would have been avoided for chargeless. (This connects up with the previous analysis if the savings after the loan were included.)

But no one ever counts the post-30 years part, usually saying it is “discounted” away. So much for the Hoover Dam – it’s just a phantom of our collective imagination. (Actually, the savings are real; it’s only the economists who guess business-defined discounting is “factual,” when in fact it is only utilized for business to make maximum of short-term benefit. It is not societally identified the same way.)

Ken Zweibel


1. u30
October 20, 2010 7:13 pm

Ken, when PV capex falls below $2,00/Wp (the marginal cost is already there) and the LCOE hits 10 cents/kWh you will get free CO2 abatement. It’s not more than 3-4 years away.

October 20, 2010 7:43 pm

I agree. We can look forward to it.

I also agree with your other comments, and will also be looking at the methane as storage option.

2. u31
solar energy home
November 3, 2010 12:02 am

I’m looking forward to it as well. I live in the southeast and for the first time I am hearing advertisements on the radio about building solar panels. Im trying to get involved with college programs and state run programs to really get my site known. ; ] let me know if there is anything I can do for George Washington Solar.