Armed with all of the smarts you've picked up reading this book, you should be able to walk through a solar home and generally figure out if it's up to snuff. If you see too many things that look outdated or that don't seem to be working properly, move on. You want to take advantage of as much of the sun's energy as you can. This section explains what you should look for as you evaluate whether a particular solar home will meet your needs.
An energy-efficiency audit is always a good idea, not just for the solar equipment, but for the entire house. You can have this done as part of the usual due diligence, or you may want to pay for it upfront before you start getting serious about the house. This audit will also reinforce your conclusions from your evaluation of the home.
Before you even set foot in the house, you can get a feel for how effective the solar features are by looking at the home's orientation, structure, and landscaping. (For information on the ideal solar home, see Chapter 19.)
1 Which way does the home face? The best bet, for solar, is a southern front, but it doesn't mean that the home needs to face the south. A good solar home will have southern windows, and the family room will be on the south, preferably with large windows shaded by deciduous trees.
1 Are the deciduous trees in the right spots?
1 Are there solar tubes showing on the roof? Skylights?
1 Do the windows have overhangs?
1 Are thermal masses being used effectively?
1 Look at the roof and see if the collectors are aligned optimally. Are they facing east or west? Could you make a few changes and get more out of the equipment? Are there trees shading the collectors that you could cut back to get more productivity? Are the collectors dirty or damaged?
You'll get a roof inspection as a matter of routine. Keep in mind that not only will you need a new roof at some point, but if solar panels have already been installed, you'll also have to pay to get the equipment dismantled first, and then reassembled after the new roof is in place. You'll also be getting no solar production during this period.
Looking at the home's design
You can change some things about a home's interior. Other things you have to live with. Here are some features to consider:
1 Is the family room on the south, with big windows?
1 Are the blinds strictly decorative, or do they also have functionality?
1 Is the fireplace centrally located?
1 An efficient home uses a large, central living space. Homes that are spread out with meandering hallways require a lot more energy to heat and cool, plus they use a lot more building materials.
1 Utility spaces should be located in easy to access points.
1 The kitchen should be adjoining the garage.
1 Windows should be functional as well as decorative. The best designs have windows that are both functional and decorative at the same time.
You'll want to carefully inspect any existing solar systems. The best bet is to have a professional check them out. (Perhaps the energy auditor is qualified to do so; otherwise, call around, but be aware that a solar contractor may try to sell you a new system.) You can check the systems for yourself, which is a good idea, because if you buy the house, they're going to become your property, and your responsibility, so you'll have to know how to operate and maintain them.
i Find out whether the systems can be expanded. For example, is the inverter larger than its current output power? If so, PV panels can be added. A hot water system can usually be expanded by adding more collectors.
i Check the PV system. You can do this by looking at the power output on a sunny day near solar noon.
1. Check the panels and see how far off the optimum angle they are.
2. Simply read the digital meter on the face of the inverter.
This will be the maximum amount of power you can expect to get out of the system.
With this information, you can determine the maximum system output, and from this amount, you can estimate the annual generation, that will yield your cost savings. (Chapter 17 explains PV systems in great deal.)
i Are there local building department permits for the equipment? Why not? You may want to insist on the seller getting this done, although she's probably going to balk because it's a big hassle.
In all likelihood, the seller of the solar structure (how's that for alliteration!) will be eager to talk to you about his home. Take advantage of his passion for his home and lifestyle and find out the following information:
i When was the equipment installed?
i Who installed the equipment?
If it's a do-it-yourself job, have the work checked out by a pro, or check it yourself, especially if you're also a do-it-yourselfer.
i Where was the solar equipment purchased? Is the company still in business? Why not?
i Who designed the solar equipment? If it's passive, was the architect or designer qualified? Temper this answer with some common sense. A pro can design a poor house, and a novice can design a great house (especially if she's read this book!). Ultimately, it's performance that counts, not pedigree.
1 How much warranty is left? Is the warranty transferable (this is important)? Have any warranty repairs been done? If so, pay attention to what went wrong. If several warranty repairs have been done, beware, especially if the warranty is about to expire.
1 What records have been kept regarding system performance and maintenance?
1 Can I look at the manuals that came with the equipment? You may be able to get these on the Internet, but a conscientious owner (the kind you want) should keep them. Read through the manuals and you'll understand the equipment and what it's going to need by way of maintenance and repair.
If you buy the house, ask the owners to leave behind the manuals and any maintenance records or other relevant paperwork for your reference.
If everything else about the home checks out, take a look at the power bills. If the seller doesn't have them, she (and sometimes you) can get them from the utility company. If you can't get any power bills, something is wrong. The seller should be proud to show them off, as the vast majority of solar home owners are.
Of course, personal habits enter into the equation, so you need to temper what you find with a consideration of how the seller's energy usage may differ from your own. This may not be easy, particularly if you're not able to talk directly to the seller. How many people live in the house? The kind of cars they drive often signals how they use energy in their home. If they're all driving enormous SUVs, it's likely you'll be able to do better on energy conservation than they do. Or you can simply ask about their energy habits, although this is a tough nut to crack.
If some monthly bills show a total that blips up inexplicably, it could be because the solar equipment was broken at that time. Ask why the bill blipped, and take warning if the answer doesn't jibe with the seller's claims of how often the equipment went down.
You also need to consider utilization, which is how much solar equipment is being used versus its maximum capacity. For example, if the house has a solar water heater, how much of its capacity is being used to offset the current power bill? If it can put out twice as much energy as it is currently, is this important to you? If your family is bigger, you'll use more hot water, and you'll probably use more energy in general. This may or may not be reflected in higher energy bills.
You should also talk to the utility company and find out the following:
1 Is there a net metering agreement. If so, does it carry over?
1 What is the rate structure going to be? If it's not going to be the same as the one in place the last few years, your utility bills are going to be different.
1 What are the new bills going to be? Now you've got some math to do, but luckily you have my expert advice to rely on.
1 Can you change the rate structure if you want?
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