# What are renewable energy credits?



## MountainStoveGuy (May 16, 2006)

Well done! 
Were all ramped up at work to start selling and installing photovotaics, there is a serious boom in grid interactive systems here in colorado. They passed amendment 37 last march where our power compay offers a $2.50/watt rebate on top of the REC credits, which it $2.00/watt, for a grand total of 4.50/watt. Installed sytems here are going for $8.00-$10.00/watt. Not a bad deal. The only problem we have is getting modules. Its great to see regular folks installing arrays and producing green energy. 

From what i understand, REC's are like stock that can be traded, is this true?


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## Rhone (May 16, 2006)

Photovoltaics are on average around 11% efficient converting sunlight to electricity with 14% their max.  They also have a few nusances, like the hotter they get the less efficient they become, and what happens to the other 85% of the energy not converted to electricity?  It's mostly converted to heat and those things get damn hot and when you think you're getting the most energy (around noon) they're working at their least efficiency.  If a branch or object just covers 1 cell of a panel its efficiency drops 50% (to around 5-6% conversion of sunlight to electricity).  So, photovoltaics just aren't there for me yet.  

There's the new method, you probably learned in your course.  That is,converting sunlight into electricity at 11% efficiency is not very practical but converting  sunlight to heat converts well.  Usually like 80% efficiency to heat something to about 150 degrees and 50-60% to heat something to extreme temperatures.  The new method to make electricity is to use mirrors that direct the sunlight to hit a ball of water to heat it into steam which that steam turns turbines that produce electricity.   That method, I believe I read is 45% efficient at converting sunlight to electricity in the end vs. the 11% of the photovoltaics and the system not hindered much if one of the mirrors is partially in shade and the hotter it gets outside and around noon when the sun is the worst the more efficient that system is which works well to feed the electricity to run people's AC units.  

I asked how much $ to put photovoltaics on my roof, I got an estimate of around I think $28,000 and would lower my electric bill by $11 a month.  I politely walked out of there realizing photovoltaics is just not there for me.  I'm happy to see Colorado offer good solar incentives, as that state is one of the best to utilize it and if I were making a solar testing green energy facility I'd pick Colorado for it's abundant sun and clear skies.  It may become the pioneer state in solar for the country.


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## MountainStoveGuy (May 16, 2006)

I wasnt looking for a opinion on there worth dylan, i was looking for how they worked. Mabey someone else can help me. From what i understand about them, they are like a share of stock. You get x amount of credits and you can put them on the open market. Are there REC brokers? Do any of you own REC's?

Rhonemas, you are correct in alot of your points. Whats strange, is that germany and japan are the leaders in this industry. Germany has a climate much like seattle, and they have a very succesfull pv plan going on out there. Monocrystalyn modules can get upwards of 18% efficiency, there hard to get and still expensive. Cooler climates like mine are definalty more likley to produce more power, high altitude and low temps make for happy pv systems. Thermal sytems are more effecient then ever, but  in my oipinion, the PV stuff is hot right now because of the incentives that the government and states are giving you to install it, also there isnt any moving parts, low mantenaince, and abundent sun. The efficieny plays a part but not that big a part. Who cares if your wasting sunlight, as long as its producing enough power to spin your electricity meter backwards. Out of pocket cost of $28,000 would be about a 4kw system. With some modest conservation measures in your home, at the end of the year you could have net zero energy usage. That works out to well above $11 dollar savings. Now for me, it doenst work out either. I dont have enough southern exposure, and i have a all electric house. It would cost a fortune and take huge amounts of southern exposure roof space, also my local co op isnt offering any kind of rebates, i would only recieve the REC credits, and the $2000 federal tax rebate. Not enough for me to make it happen. I do buy my power from wind generated sources, it costs alittle more but its the best i can do for now. The studies out here are pointing towars a 9-11 year payback on a pv system, figuring that you will buy it from the power company for .11/Kwh. Also from a resale standpoint, 104% of the system cost will be paid back when you sale your home. That came out of california data. California is currnenty the pioneer state. Even home depots sale PV in california. Colorado is supposed to be the next big one. We will see.


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## BrotherBart (May 16, 2006)

From what I understand RECs are available in certain states to retail energy producers. They can in fact sell or trade them with other retail producers. They get X amount of credits for using a, narrowly defined in each locality, renewable source for producing energy

I am sure there are more out there but this outfit is the only broker I know of.

http://www.evomarkets.com/


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## MountainStoveGuy (May 16, 2006)

Thank you.


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## wg_bent (Jul 17, 2007)

An interesting related link to this discussion:

NY solar cost estimator

plug in some numbers... Why is there a federal tax increase for installing PV system?  Looks to be offset by NY credit, but why bother?  Are the feds nuts?


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