Considerations for choosing a solar panel provider
February 26, 2013 4:19 AM   Subscribe

If I buy solar panels for my home, what are things that I need to consider in the supplier and product?

With the many suppliers/resellers out there, and the wide price differences with some offering several thousand dollar and others relatively cheap as chips, how do would I decide?

What are the range of expectations in terms of quality, aftersales service and bang for buck, if we're talking about a ROI of 5-10 years?

Bonus questions:
Is China-made better quality?
Are there ratings or standards to identify quality?

Thanks MeFi!
posted by gttommy to Technology (10 answers total) 4 users marked this as a favorite
All of the cells will be made in China, but the modules may be fabricated elsewhere, or locally.

What type of system are you looking at - off grid, or net metering? If on-grid, central or micro inverters? Everything has to meet electrical code, and (if installed on your roof) be acceptable to your insurer.
posted by scruss at 4:30 AM on February 26, 2013

Best answer: All the technologies come with different tradeoffs, though competition means they all offer roughly similar watts per dollar.

If you have limited roof space, you'll probably want monocrystalline panels as these have the highest watts per square metre; amorphous panels will take up rather more room per watt, but are better at preserving their output rating over time and temperature. Monocrystalline panels will be down to maybe 80% of initial rated output after 20 years, and also sag quite a lot on really hot days. Amorphous panels just keep on keeping on.

I don't know how thin-film panels will perform in 20 years - they haven't really been around for that long.
posted by flabdablet at 5:11 AM on February 26, 2013 [1 favorite]

Response by poster: what's best for typical suburban house?

Would on-grid be the way to go?
posted by gttommy at 5:11 AM on February 26, 2013

Oh, and all I can tell you about cheap-as-chips suppliers is that mine got gobbled up by a larger outfit, and I am now experiencing extreme foot-dragging on getting my failed grid-interactive inverter repaired under warranty. Were it not for the fact that I squeaked in under the tape of a government subsidy scheme that paid 100% of my installation cost, I would be quite pissed off about all that lost feed-in revenue.
posted by flabdablet at 5:14 AM on February 26, 2013

If you already have a grid connection, grid-interactive solar should be pretty much a no-brainer Yes - but there may be gotchas in the fine print. You might be required to change your meter type, and if you do that, you might then find that certain discount supply offers are no longer available to you. That, in turn, means that you really really want power to be flowing out of your house most of the time, to compensate for the lost discounts on supply; which in turn means you should probably stick up as many panels as you can possibly afford. And once you've done that, you'll probably find that cutting your supply scheme over to 100% Green will cost you very little; and once you've done that, you should find that all the carbon tax compensation stuff becomes pure win for you over time. Until, of course, we let Big-Ears take over the Noddy car and drive us back into the weeds again.

Don't deal with Simply Energy if you have a choice - they're almost completely clueless about billing in general and grid solar in particular. Origin aren't too bad.
posted by flabdablet at 5:23 AM on February 26, 2013

Here's good article (written by an installer):
Grid-tied, Grid-connected, Off-grid. What's the difference?
posted by 445supermag at 7:00 AM on February 26, 2013

Best answer: I'd suggest picking an installer company that gets good recommendations, and then discussing the technology options with them -- they're going to know what's out there, have a stake in keeping up with the best options, and be able to explain the pros and cons of different choices (e.g., having a battery versus being attached to the grid, what your local regulatory constraints might be, etc.) and what you can expect to see in terms of yields on your site. Plus, a good team will walk you through the regulatory/tax credit processes and/or guarantee you something if the regional incentives fall through. All that is much more important to your happiness than the name printed on the panels, which is going to be one of a constantly changing set of possibilities.
posted by acm at 7:05 AM on February 26, 2013

We installed solar panels about 3 years ago through a program promoted by a non-profit called "One Block off the Grid". They connected us to a local installer. We decided against purchase because we found an option through a company called SunRun at much less cost, where they install and maintain panels at their expense and we transferred the tax breaks to them. They essentially lease our roof and sell back electricity to us at a set (low) price per kw. As I understand it they make their money back in the first few years and the equipment then has minimal value to them. Technology will have marched on, but solar cells have few moving parts and will presumably continue to produce current, though probably not as effeiciently as cells will in the future. At the end of the 20 years we can purchase the equipment at a depreciated price or have them remove the panels. We needed to install double meters, which they did, again at their own expense. We are definitely tied into the grid in the middle of a huge city, so it doesn't help us during the very rare electrical black-out.

The amount of electricity we can purchase is limited to the amount we can generate. I think they were able to fit 12 panels, but it's reduced our bill by about 20%. If you live in a location where it costs more to use electricity during the sunny summer, you'll make out better because the spread between your prepurchase price (set at that low rate) and the going rate is greater. Not the case where I live, but that could change, I suppose. Cost savings was only part of why we installed the panels.

This cost us about $8500, as opposed to purchase outright, which was estimated at $25,000. There were lower-cost installation options where the electricity break was less, as well.

I live in a townhouse and have a flat roof with absolutely no shadow at any time of day - they did an inital Google aerial view before even considering my property. If you have trees or other shadow-producing structures it makes solar much less efficient.
posted by citygirl at 8:32 AM on February 26, 2013

IEC/TUV certifications are most common for modules. ask for warranties on performance should be comparable to 90% power output in first 10yrs and 80% in first 20years.

The main criteria to compare however is efficiency.
posted by Under the Sea at 9:00 AM on February 26, 2013

We just did the same thing as city girl, except we didn't prepay for the electricity. We used Solar City. In fact, our city inspection so they can turn on the panels is this morning!
posted by reddot at 5:28 AM on February 27, 2013

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