Secondary Concerns You May Have About Solar

In considering solar, people often have questions or concerns of secondary importance: installation, appearance, use, maintenance, payback period, selling a house with solar, and environmental benefits.

These are in addition to the 4 main questions to consider when deciding whether to shop for a solar-PV (photo-voltaic) system: (1) Will solar pay, how much, and when? (2) Is your house suitable for solar? (3) Can you afford it? and (4) When is the best time to acquire it, now or later? The Solar Buying Guide - Step 1: Whether Solar Makes Sense for You is exactly what people need to answer these questions correctly for themselves.

This article gives brief answers to these secondary questions.

Solar Installation

You needn't be concerned about installation time and inconvenience, so long as you use an excellent installer. It can often be done in only a few days, and usually doesn't take more than a week. You don't have to be home while the work is being done, and it's not nearly as disruptive or dirty as having a roof replaced.
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Solar Panel Appearance

A high-quality array can look very nice and quite unobtrusive, if mounted close to the roof with a good rack. And it need have no adverse impacts on your roof's waterproofing, if installed by an excellent installer.
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Using Your Solar System

There's nothing to it. There's nothing for you to do except monitor your solar production if you want to, which is easy to do.

The system connects to the utility's electricity line that is already coming into your house. The electricity your system produces goes first to supply your needs at that time, with the surplus going back to the utility company for credit to you (called Net Energy Metering or NEM). Since you will be on a Time of Use rate schedule (TOU), most of these credits will be at the higher rates per kWh that apply during on-peak hours (2:00pm to 8:00pm weekdays for SCE/Southern California Edison).

If your system doesn't produce as much electricity as you're using at that time, the utility supplies the extra and charges you only for that extra amount. When the PV system isn't producing anything (as at night), you draw all the electricity you use from the utility company, just as you do now, but most of that will be at the lower rates for off-peak and super-off-peak hours. That way, you pay at low rates for most of the electricity you use and are credited for sending surplus electricity back to the utility at high rates. This differewnce contributes significantly to your electricity cost savings.

If you want to get off the utility grid completely, you can even install a battery to store up the energy you produce during the day for use at night. They're pretty expensive right now, but costs will be coming down.
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Solar Maintenance and Monitoring

It's as simple as rinsing off the panels twice a year with soft water. But severe contamination, such as from a fire, can reduce production by as much as 30%. You can clean it yourself or hire someone to do it.

Monitoring your system's production can be done on your account on the solar manufacturer's website.

If something goes wrong (rare with good systems), the best manufacturers have a warranty for 25 years against everything. Either you will discover the problem by monitoring or the manufacturer or installer will catch it. A service call from your dealer, if a good one, should result in quick replacement of anything defective.​
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Solar Payback Period

 If you stay in the house on which you installed a PV system for enough years, you will have saved as much in utility costs as you paid for the system. This is known as the "payback period." My calculations under my assumptions of a good quality system on an ideal house with optimum financing are about 9 years.

Each year you live in the house after the payback period is just gravy. Since the best panels will last approximately 40 years, declining only .25% per year in output, our sample homeowners would have 30 more years of nearly free electricity.
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Selling a House with Solar

But what happens if you want to sell your house before you reach the end of the payback period? Do you lose the difference between your electricity savings to that point and the cost of the system? Certainly not.

A PV system adds to the value of a home, although how much it adds is tricky. Most real estate agents and appraisers haven't had enough experience selling solar homes to know how to value a PV system correctly, but this is changing fast, and new academic studies are helping.

The most recent and accurate study of this topic is the latest one by the Lawrence Berkeley National Laboratory in November 2015.* It gives very strong evidence that if you sell your California house before completing the payback period, you are likely to get back more for the PV system than you paid for it.

​That means, for example, if you finance it with an interest-only loan, your only cost for the system is the interest on the loan. This issue is taken up in depth in the Solar Buying Guide - Step 4. But for now, this should reassure most prospective buyers that they won't lose money on a PV system, no matter when they sell their house. (The complete treatment of this complex subject is at Solar Increases Home Value.)
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Environmental Benefits of Solar

They're huge. California alone is likely to save almost $27 Billion over the next decade by lowering carbon emissions, reducing air pollution, saving water, and reduction in land use for power plants. Please see Environmental Benefits of Solar for the full story.

Once these 7 issues are properly understood, they needn't trouble the vast majority of prospective solar shoppers.

                                    
* Sandra Adomatis and Ben Hoen, “Appraising Into the Sun: Six-State Solar Home Paired-Sale Analysis, An Analysis for Appraisers and Other Valuation Professionals” Lawrence Berkeley National Laboratory, November 12, 2015.