Alternative Energy Q&A - Ask me about Solar or Wind Power

Might be a good idea to explain SRECs and TRECs for those who might have them in their area. I stumbled onto it while searching and never knew it existed. It looks like you generate credits and sell them on the open market (some states are open to outside SREC sales).

How many credits could you get from a system that's about 5KW? California has TRECs. I couldn't tell if those were something that only benefits large producers.

 

Here's a couple:

What's the minimum wind speed and duration that you would need to make a wind system pay for itself? We're going to be living near the top of a hill and I can feel the wind come in as the sun goes down. I'm just not sure it would be enough to be useful. Is there an easy way to measure and monitor it?

Is a hot water solar system a bigger bang for the buck than electrical solar?
I've seen where people are building their own and it looks fairly easy.

I've also seen people who build their own electrical solar panels but given the state of the industry, it looks like building a panel doesn't save much money given the output of the newer panels, especially when you consider the amount of time it takes to build one and the amount of roof space you would require. They typically generate about 80 watts whereas a Kyocera or Sharp panel can generate up to 240 watts.

What brand of solar panels do you recommend? I've seen some say to avoid the Chinese-made panels and stick with Sharp or Kyocera.

I've heard that thin-film panels are gaining a lot of traction because they are easy to lay out. They don't output as much but they also don't degrade in hot climates.

What's better, Poly or Mono?

That should keep you busy for a while.

 

^ on the phone right now when I get in front of my computer i'll answer. Lots of good questions

 

SREC's check this out for detailed description: http://en.wikipedia.org/wiki/Solar_Renewable_Energy_Certificates

Basically a tax credit extended to an owner of a solar electric system. I am not certain how it works in california but here when the utility pays a rebate the are then able to hold onto the SREC's. Even when they do a Feed In Tariff the utility holds the SREC.

I am not familiar with a TREC.

 

Answers in red...

Here's a couple:

What's the minimum wind speed and duration that you would need to make a wind system pay for itself? Every wind turbine has its own cut in/out speed. I usually use 4.5-5mps (meters per second) as a rule of thumb for a minimum yearly average. We're going to be living near the top of a hill and I can feel the wind come in as the sun goes down. I'm just not sure it would be enough to be useful. Is there an easy way to measure and monitor it? Keep in mind that what you feel at ground level is very different than what the turbine feels 80 to 120 feet up in the air. There are many wind maps that can give you a good idea of the wind in your area often you local utility will have these maps if they have any incentive program. It is difficult to monitor or measure the wind because the only accurate way to do it is to get up to the height that the turbine would be located so you would need a tower or a pole first.

Is a hot water solar system a bigger bang for the buck than electrical solar?
I've seen where people are building their own and it looks fairly easy. You can certainly build your own hot water system. I have seen them as simple as a black plastic tub that sits out in the sun. I often recommend solar electric over solar thermal because the incentives, rebates and tax credits, are typically better for solar electric. That being said solar thermal has a lower price point so it is often more attractive.

I've also seen people who build their own electrical solar panels but given the state of the industry, it looks like building a panel doesn't save much money given the output of the newer panels, especially when you consider the amount of time it takes to build one and the amount of roof space you would require. They typically generate about 80 watts whereas a Kyocera or Sharp panel can generate up to 240 watts. I wouldn't recommend building your own solar panels unless you are looking to do an "off grid" system. Even then you just can match the power density that you get from a commercially built panel.

What brand of solar panels do you recommend? I've seen some say to avoid the Chinese-made panels and stick with Sharp or Kyocera. I install a tremendous amount of SunPower panels. They have some of the highest power density and have a patented technology (back contact) that allows them to be more efficient. We have seen what we call the SunPower factor; about 2% over production from expected output. I wouldn't say to stay away from Chinese made panels, they have some state of the art factories over there. One panel I like that is made in China is Canadian Solar. It is well made, has a great warranty backed by a third party and is very affordable. Sharp is a good panel too and I though Kyocera was no longer being made (but I may be wrong).

I've heard that thin-film panels are gaining a lot of traction because they are easy to lay out. They don't output as much but they also don't degrade in hot climates. Thin-film has its applications. You are right the power density is very low often around 5w/sqf vs 16w/sqf of crystalline. That being said it does handle high temperature better and it will also tolerate shade better. In my market it usually comes down to maxing out the roofs production so thin-film doesn't see much action. I have installed a lot of solar laminates on standing seam metal roofs mostly due to aesthetic concerns. The laminates are an amorphous silicon or thin film but the company that manufactured them has recently gone under. Another company has bought the tooling but I'm not expecting much from them.

What's better, Poly or Mono? Its debatable but in the real world I don't see any difference except price which favors the poly.

That should keep you busy for a while.

 

Just so more folks get a chance to see this...

 

A few pictures of one of my recent projects. It is a Bergey XL-S 10kW unit on an ARE 120' MonoPole. It should produce around 16000kWh of power per year.

 

I knew there had to be a thread around here anywhere.

I would love to build my own solar setup for my home one day. Seems like an interesting project to tackle.

 

Been there, done that. LIved off grid for 6 years, then installed a 10kw system that sells to the grid, and a service for the house and outbuildings, in 2010.

If you're starting out thinking that off grid will save you money on electric bills, think again. Even the most expensive time of use power is cheaper than home grown...but not as tasty!

Educate yourself about batteries! Get a good hydrometer at the start. I was left with default charge settings woefully lower than what my batteries needed, and no way to really check their state of charge (hydrometer). Aged the bank 5 years in the first year I'm sure. The original Surrette set is still there after 14 years, but coddled along, no large cycling up and down now that I have utility power for charging. I can also use the utility to carry the house loads while the wind and sun charge the battery bank. 2.5 seasons per year are without any utility power used, 1.5 season have some utiilty power used weekly, if not daily.

Not for everyone, but fun to mention a high utility bill of over $60! No-one has smacked me yet, but I imagine some have wanted to.

Ralph

 

nice!

Ill look into Hydrometers.. Never heard of them..

 

Hydrometers can be had at auto supply places (not great but work for $10), or better yet try a lift truck service/sales company. Battery supply houses might sell them too. The best ones have little glass nubs on the float to keep the float from sticking to the side of the barrell and giving an erroneous reading.

Ive used cheapos and expensive ones. When care is taken to keep the float off the walls of the barrell the readings come out identical. Hydrovolt is a plastic type, but the suction tube is too short for deep batteries. Refractometers are precise, but you have to start out with a very good calibration source...never worked for me, but it's in my inventory of tools bought but seldom/never used.

The price of pv systems has come down drastically in the last 15 years, mostly due to the falling price of photo voltaic panels. Inverters, charge controllers, racking for panels and batteries still keep the prices up there however. My first pv panels cost about $10 per watt, watt, not Kilowatt. 2.1kw of panels were over $20,000cdn. Now they can be had for under $1 per watt. Every new house built should have some minimum component of renewable energy included in it's construction. Pv, hot water systems, net metering etc.

Are you in a chopper in your avater pic?