Solar panels

JasonWatts · **Posted:** Wed Jun 18, 2014 10:51 am

Has anyone here ever looked into adding solar panels in the past few years? I'm looking into it and with all the incentives you get it seems worth it but II'mwondering what the real ccosts are and not what the companies that want my money think

thanks

Aaron Buckley · **Posted:** Wed Jun 18, 2014 12:54 pm

Run a search. I believe Mike Whitney had a thread about this a couple of years ago. - AB

Cash Davidson · **Posted:** Thu Jun 19, 2014 4:19 pm

I assume you are considering solar electric (as opposed to solar thermal).

"Putting my EE hat on"

I have looked at this MANY times for both personal use and for work (Duke Facilities). I also took a graduate level class on photovoltaics at NCSU back in the day. The short answer is: The technology STILL isn't there yet. When you do the LCCA and consider initial cost, efficiency, expected life, etc - the payback exceeds the expected life of the system often by a wide margin. Tax breaks and incentives will narrow that gap, but often not enough - especially in NC where our annual sun harvest hours are much lower than a place like AZ.

The root problem is high initial cost and low efficiency. Commercially available solar cells are less than 20% efficient - meaning of all the energy from all the light photons that strike the cell, less than 20% of that energy is converted to electricity. This is only slightly better than it was 25 years ago when I was at NCSU - at that time it was 14%. This low efficiency is why you need very large arrays, which drives the cost up. There are researchers that have hit 45+% using very exotic (read expensive) materials, but they are not commercially viable.

Bang for your buck, It is hard to beat solar thermal. Why? Low initial cost and high efficiency. Using the sun to heat domestic water, heating water, pool water, etc is a proven technology with short paybacks. In a relatively small footprint, you can often generate more HW than you can use.

Vincent Keene · **Posted:** Thu Jun 19, 2014 4:22 pm

I think we should have bought James a solar array for his going away present. Oh wait, those things need sunlight to work so never mind.

JasonWatts · **Posted:** Thu Jun 19, 2014 5:18 pm

Vincent Keene wrote:

I think we should have bought James a solar array for his going away present. Oh wait, those things need sunlight to work so never mind.

Funny.

In all seriousness I was reading some people saying on rainy days their systems still crank out a surprising amount of power.

JasonWatts · **Posted:** Thu Jun 19, 2014 5:28 pm

Cash Davidson wrote:

I assume you are considering solar electric (as opposed to solar thermal).

"Putting my EE hat on"

I have looked at this MANY times for both personal use and for work (Duke Facilities). I also took a graduate level class on photovoltaics at NCSU back in the day. The short answer is: The technology STILL isn't there yet. When you do the LCCA and consider initial cost, efficiency, expected life, etc - the payback exceeds the expected life of the system often by a wide margin. Tax breaks and incentives will narrow that gap, but often not enough - especially in NC where our annual sun harvest hours are much lower than a place like AZ.

The root problem is high initial cost and low efficiency. Commercially available solar cells are less than 20% efficient - meaning of all the energy from all the light photons that strike the cell, less than 20% of that energy is converted to electricity. This is only slightly better than it was 25 years ago when I was at NCSU - at that time it was 14%. This low efficiency is why you need very large arrays, which drives the cost up. There are researchers that have hit 45+% using very exotic (read expensive) materials, but they are not commercially viable.

Bang for your buck, It is hard to beat solar thermal. Why? Low initial cost and high efficiency. Using the sun to heat domestic water, heating water, pool water, etc is a proven technology with short paybacks. In a relatively small footprint, you can often generate more HW than you can use.

I understand what your saying about the efficiency of the panels. I have someone coming to do an estimate (free) with Dukes incentive ($1k for every 1kwh) plus the 65% I would get back from sate/Federal taxes it cuts the cost down to about 5k out of my pocket. Factor in my lack of an electric bill and the 5kw system I based my cost off (will that even fit on my roof?) and I will break even in a couple years. also I think a 5k system will surpass my electric needs and I would be putting power back into the grid and actually paid for it.

im still looking into and researching this. I found the other thread mentioned and this does all seem interesting and long term seems financially feasible/smart. This is all of course based off what has been said on the internet and I wont really know until I start getting real numbers and understanding how to use the tax credit/rebates.

JasonWatts · **Posted:** Thu Jun 19, 2014 5:39 pm

so, looks like the duke incentive is now 500 not 1k per kw

Les Davis · **Joined:** Fri Aug 29, 2003 2:04 pm **Posts:** 2059

Cash Davidson wrote:

Bang for your buck, It is hard to beat solar thermal. Why? Low initial cost and high efficiency. Using the sun to heat domestic water, heating water, pool water, etc is a proven technology with short paybacks. In a relatively small footprint, you can often generate more HW than you can use.

My Florida house came with solar water heater and it totally rocks so far. It uses zero electricity as it is a passive system that uses convection to fill the tank. It has an 80 gallon tank so way more than I can use, and probably plenty for a family of 4 or 5. Even on cloudy days it produces scalding hot water. Not sure exactly how much it saves me as I never had this house without it, but I'm sure its a fair amount. The one on the roof here is 20 years old and still seems to be going strong.

Cash Davidson · **Posted:** Fri Jun 20, 2014 12:24 pm

Jason,
The stuff to look out for are the estimates these companies make and what they are basing their data, calcs and projections on. They often over estimate the amount of sun-hours, the energy output and system life while at the same time they generally under estimate the maintenance and operational cost. As an industry, the real life payback is almost always worse than advertised.
Good luck!
Cash

JasonWatts · **Posted:** Fri Jun 20, 2014 12:34 pm

Yeah i get that. I'm just not sure how much bs there really going to give me. I figured there was maintenance on these things but i still haven't found anything yet telling me what to expect or that there is. I'm still look for real like examples on these. The one i have found sounds like it is giving a lot of positive benifits. But i want to rread about it from more then one person.

It's likely i won't do this. But maybe even after i cut out the bs it will still make since.

Cash Davidson · **Posted:** Fri Jun 20, 2014 12:54 pm

Another reason companies (and places like where I work) don't jump into this, is the long term uncertainty of regs and incentives. If you are doing a project with a 10yr payback and the regs change in 5yrs, you may be screwed.

What most people don't understand is there is NO financial incentive for Utilities to be involved with on-site renewable power (Solar, wind, etc at the customer's site). It is not because they hate renewables or on-site generation. They love on-site generation if it can offset their load and become part of the "system" capacity. The problem with solar and wind is they are only available when the sun is shining or the wind is blowing. If you want to deploy these renewables and cut the cord to the grid, they would be happy with that, but instead you are saying, "I'm going to generate my own power sometimes, but I want you to be ready to meet 100% of my power need at anytime I'm not generating power - oh, and if I generate extra power, I want you to buy it from me." So the Utility still has to have that connection to your house maintained and functional and they need to have generator capacity available for 100% of your load in case you need it - they have avoided no infrastructure cost when you installed your solar/wind system.

Conversely, I have a 3.2MW diesel generator plant at work. The Utility sends me a check every month if I keep it ready to run whenever they ask. Generally 3-4 times a year, they will call and ask us to run it for 3-4hrs. They are willing to do this because it allows them to meet their peak demand (which only occurs a few times/yr) without building more capacity. It also allows them to take some capacity offline for maintenance without having to build redundancy.

Rob Keehner · **Posted:** Sun Jun 22, 2014 9:57 pm

Solyndra cells are on ebay cheap these days and they can help with production of electricity by not being so sensitive to the angle of the sun.

Donnie Barnes · **Posted:** Sun Jun 22, 2014 11:27 pm

Cash Davidson wrote:

Jason,
The stuff to look out for are the estimates these companies make and what they are basing their data, calcs and projections on. They often over estimate the amount of sun-hours, the energy output and system life while at the same time they generally under estimate the maintenance and operational cost. As an industry, the real life payback is almost always worse than advertised.
Good luck!
Cash

But if the payback is as bad as you say, how are there companies out there offering to put a system on your house for FREE? The kicker is you only get something like 1/3 of the benefit and they sell the rest to the power company and THEY profit from it, but you have zero cash outlay. Obviously the big fear here is they screw your house up doing the install, but otherwise it seems fairly risk-free. Is there some catch I'm missing?

I don't know who does it and haven't REALLY looked into it, just saw a quick news story blurb a couple months ago and wondered about it. It can't be a good deal for folks who *could* afford to buy their own system, but for someone who can't, it seemed like a reasonable idea, anyway.

--Donnie

Jason Mauldin · **Posted:** Sun Jun 22, 2014 11:48 pm

What happens to the shingles beneath the panels? Will the panels need to come off every so often to service the roof?

clinehall · **Posted:** Mon Jun 23, 2014 1:36 pm

Donnie Barnes wrote:

Cash Davidson wrote:

Jason,
The stuff to look out for are the estimates these companies make and what they are basing their data, calcs and projections on. They often over estimate the amount of sun-hours, the energy output and system life while at the same time they generally under estimate the maintenance and operational cost. As an industry, the real life payback is almost always worse than advertised.
Good luck!
Cash

But if the payback is as bad as you say, how are there companies out there offering to put a system on your house for FREE? The kicker is you only get something like 1/3 of the benefit and they sell the rest to the power company and THEY profit from it, but you have zero cash outlay. Obviously the big fear here is they screw your house up doing the install, but otherwise it seems fairly risk-free. Is there some catch I'm missing?

I don't know who does it and haven't REALLY looked into it, just saw a quick news story blurb a couple months ago and wondered about it. It can't be a good deal for folks who *could* afford to buy their own system, but for someone who can't, it seemed like a reasonable idea, anyway.

--Donnie

I have a client that does this for his business. I'm not sure if I understand it correctly. I THINK what he does is get a grant for some kind of rural economic incentive thing that pays him for the matarials and maybe labor install. He then finances your portion to be paid for as your tax incentives come in. You then get a small check from the unitiliies company as they are forced to buy your electricity back. This system does not do anything to power your home. I can't remember the numbers but they have to pay you more than they sell it for. To me it sounds like a federal government boondoggle.

I had another client of mine do it, he did not qualify for any incentive so he took out a second mortgage. Said it will be paid off in 10 or 20 years with his tax credits. My thought is you then have 10 year old technology on sitting on your roof.

I'm a sceptic.

Here is his website:

http://www.greenpowernc.com/ his name is William Smith. I'm not endorsing it but I'm sure he will talk to you about it. He also does my IT and business phones!

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