21 Things to Know Before You Go Solar
By Bruce Karney*
1. Energy efficiency is the simplest method of saving money and the
environment. Any reputable solar salesperson should give you one
piece of advice: first conserve. Identify electricity wasters in your
home and repair, or replace. A web search on "conserving electricity"
will give you great ideas.
2. There is a lot of information about new solar panel technology, but most affordable modules use the same basic technology that has been in use for fifty years, with improvements in degrees of efficiency and aesthetics. Solar panels are a proven, long-lasting way to convert sunlight into electricity. The latest models convert about 18% of the energy that strikes them into power. New technologies for the most part are only applicable to very large commercial installations.
3. This system will not take you “off the grid.” During the day, the sun produces electricity you use through the system, and sends the excess into the grid. If you produce more than you are using, your meter runs backwards. At night, you get your power from PG&E's grid, just like you do today.Review your electric bills for the past 12 months. PG&E electricity rates currently bill in five tiers. These are: Tier One: 11¢; Tier Two: 13¢; Tier Three: 25¢; Tier Four: 35¢; Tier Five: 41¢ per kilowatt hour
When you add a solar system to your roof, you replace the top tiers first. The more you spend on electricity now, the higher the return on investment you will get from a properly sized solar system.
4. Solar panels, warranted for 20-25 years, historically have lasted about 30 years, losing approximate 0.5% of their efficiency each year. Generally, the only maintenance is to hose them off a couple of times each summer. The inverter, which converts direct current produced by the panels to alternating current used in your home, warranted for 10 years, may need to be replaced in 10-15 years. Currently, the cost for this is about $2,000 for parts and labor.
5. A southwest-facing roof is ideal. However, most roof directions will provide an adequate amount of electricity.
6. Know exactly how much electricity you use each month. You can request the data from PG&E. Think about how your electricity needs might change in the future. Family and business changes, plans to purchase hybrid or electric vehicles, planned energy efficiency upgrades will make a big difference in the amount of electricity you use. Ask the salesperson to base their bid on your PLANNED electricity use, not necessarily your current use.
7. Shade is a vital factor. A solar salesperson will climb on your roof and use a tool which calculates how much light and shade are produced in different seasons. You should consider the growth of trees over 10-30 years. Some trees that shade your roof may be on neighboring property. Consider what tree maintenance may be required over the life of the system.
8. For a purchase, State rebates and Federal tax credits are important for the cost/benefit decision. California state rebates decline as more systems are installed. In October 2008, the maximum rebate for residential installations is $1.90 per AC watt and this is expected to drop to $1.55 in mid December.
The Federal Investment Tax Credit has just been renewed and starting January 1, 2009, will extend to 30% of the purchase price of your system. This is a substantial savings.
Starting the process now and having the system finally completed in 2009 gets you the best possible return.
9. Many families that go solar switch to Time of Use metering. This means that PG&E charges more for electricity in times of high demand. PG&E’s E6 summer time of use rates are: Peak 21¢, Partial Peak 11¢, and Off-peak 09¢. Your solar salesperson can help you decide whether Time of Use rates are right for you.
10. It is very difficult to know how much a solar system will add to the value of your home at resale. People who install solar systems generally plan to stay in their homes a long time, so re-sales are rare. 5 or 10 years from now potential buyers will be much better able to assess the value of a low electric bill.
11. Installing solar electric does not eliminate your electric bill. PG&E will buy your excess power, but only to the extent that it drives your net annual electricity bill to zero. They will still charge you a monthly "account fee" that covers services like line maintenance and meter reading. PG&E will, however, take all the power your system produces in excess of your needs, so you should not oversize your system.
12. Some solar system critics have said that the energy produced by solar panels is less than the energy it takes to make them. This is simply false. The energy required to manufacture solar panels and inverters and transport them to your home is equal to about 1 to 3 years worth of the energy produced by the PV system.
13. You can buy a solar system with no money down. If your credit is sound, you can either lease a solar system or purchase one with a home improvement/home equity loan. In either case, if you now pay more than $150 monthly for electricity, your total monthly bill will be lower. In other words, your PV system will put money in your pocket every month from the first day you install it.
14. Going solar will not trigger a property-tax reassessment of your home. By law, reassessments can only be triggered by improvements that expand the size of your home.
15. Once your panels are on your roof, you should tell your homeowner's insurance agent so that they can be added to your policy. This may increase your property insurance but it's important to make sure that your solar investment is protected from damage by fire and the other perils that your homeowner's policy covers.
16. Two kinds of solar system warranties are typically offered. Manufacturers' warranties are typically 20-25 years on the panels and 7-10 years on the inverters. The solar installer should also warranty the quality of their work. For example, the installer will warranty that your system will operate properly and that there will be no leaks in your roof for a period of time, typically 10 years. (However, neither the manufacturer's nor installer's warranties cover fire or theft, which is why you need to add them to your homeowner's policy.)
17. Solar panels will not damage your roof. Sunlight causes the most damage to a roof. In fact, the panels protect the area directly beneath them from light and heat. The shade provided by solar panels may cool the rooms below, even though the ceiling is well insulated.
18. Speaking of roofs, it will cost more to mount solar PV panels on a particularly steep, Spanish tile, shake, or tar and gravel roof, or one that is difficult to access, than on composition asphalt shingle roof. Some roofs require that more care must be taken to insure that the attachment points that penetrate the roof are properly sealed. This may add 10-25% to the cost of the job.
19. The pitch (or slope) of the roof affects the production you can expect from your solar system, and may also affect the cost of installing it. Pitch interacts with orientation (e.g., south-facing or west-facing) in a complex way that will be computed by your sales representative. In general, a pitch of 18-22 degrees is ideal. If your roof is flat, panels can be mounted flat or "racked up" at the ideal angle to generate more power. In some cases, racking may cost more to install. If your roof is particularly steep the crew working on it will need to use safety harnesses, which may also add to the cost.
20. The only routine maintenance a solar system requires is occasionally hosing off the panels. Accumulated debris decreases the power the panel can produce. This is most noticeable if your panels are mounted flat or at a low angle, and less so if your roof is steep. One good rainstorm is all it takes to restore them to full production.
21. Because solar systems have no moving parts, you may wonder how you can tell if your system is working. Once it is installed, you will be able to see that in two ways. The first is the display on your inverter, the device that changes the direct current (DC) from your solar panels into the alternating current (AC) you actually use. The display on the inverter will tell you the instantaneous power output and also the amount of energy produced so far that day in kilowatt hours. The inverter can also tell you the total lifetime energy production from your system. Some vendors also include monitoring services which provide far more data, including the option to track production by hour, day, and season on your computer.
*Bruce Karney originally wrote this list when he was a homeowner organizing his Mountain View community to buy solar as a group. His group selected SolarCity and the program resulted in 119 solar installations. Bruce is now a Financial Analyst at SolarCity.
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