As complex as they may seem, you don’t need a doctoral science degree to understand and use basic solar power setups for your home.
“A lot of people associate solar power with expensive, high-tech, solar-panel arrays, and assume that the technology is unaffordable and way too complicated,” observes Eric Smith, author of DIY Solar Projects: How to Put the Sun to Work in Your Home. “But the truth is you can harvest free energy from the sun in a lot of different ways.”
Smith’s book delves into dozens of projects utilizing solar energy and heat to generate the power required for everything from charging a cell phone to supporting your home’s hot-water needs. We asked him to expand on the concepts behind some of these projects, as well as what consumers can expect in attempting to construct them on their own.
Q: What was your key purpose in writing this book?
A: My main purpose in writing this book was to show how you can use solar energy right now, using standard, inexpensive materials from home centers. I also wanted to demystify the process of generating electricity from photovoltaic (PV) panels.
The PV kit project we show on the cover is simple enough for a beginner to put together — you just set up the panels and plug some wires into a controller box, and the lights magically come on — but once you see that, a large whole-house system becomes easier to understand because it’s basically the same system, just scaled up.
Q: What aspects of solar technology do you find are most confusing for consumers to grasp?
A: It’s kind of hard to grasp how simple it really is. “Solar technology” sounds like something you need a physicist for, but solar energy is all around us, waiting to be put to use. Put a black shirt on, and stand in the sun, and suddenly you’re an efficient solar collector. It’s so familiar and obvious that we never even think about it, but the idea of wearing a black shirt leads to painting pipes black and running water through them, and all of a sudden you’re saving real money on your utility bill, just the same as if you put solar panels on your roof.
Q: Obviously, costs will vary depending on the project and scope of the solar power consumers hope to derive from the setups you list, but on average, could you guesstimate how much consumers stand to save by doing these projects themselves?
A: A DIY solar water heater with a storage tank ($800-$1,500) or air collector ($100-$200) would be about one-third to one-quarter the cost of a manufactured system installed by a contractor. For PV systems, you’d save the cost of installation, which might cost as much as the panels depending on how much wiring has to be done.
Q: How much will quality of product affect the effectiveness of these projects?
A: You can always save by using recycled building materials, but there are no cheaper substitutes for some of the products; for instance, you have to use more expensive foil-faced insulation because it has a higher R-value and it stands up to high temperatures better than Styrofoam.
However, there are many other designs out there for all of these projects [listed in the resource guide] — some of them less expensive. For instance, you can make a perfectly good solar cooker from a cardboard box and tin foil for a few pennies. [See the following excerpt for Smith’s take on the solar cooker setup.]
Q: You make note of certain instances in which professionals should be called in, at the very least to conduct inspections, and many of the larger solar-heat projects require a fair understanding of woodworking. What basic skills should consumers possess in order to tackle the larger home projects?
A: For the solar-heat projects, you should have standard power and hand tools, and be comfortable using them, and have some experience with basic carpentry, plumbing and wiring. However, none of these skills are hard to learn.
For a small PV installation like the one on the cover, all you need is a basic familiarity with wiring, but for larger installations, you’ll need more knowledge. Suppliers can put together a system for you, but you have to understand how it works and what the different components do. You also need to pull a permit and get your work inspected — a process that’s much easier if you know what you’re talking about.
Q: You make note that certain systems can be added onto as needed. How difficult is it to retrofit these systems to generate more solar power? Do plans for additions need to be determined in advance?
A: You can always make your system larger, but you can save some money if you size the components and wiring for future expansion when you first set up the system, so you don’t have to replace undersized components later. Discuss it with the supplier you buy from or with an electrician.
Q: What common mistakes do consumers make in attempting to tackle installation of such systems themselves?
A: Water leaks on roofs are fairly common. Anytime you attach something to or drill through the roof, you have to make sure the flashing details are right. Don’t rely on caulk alone to keep water out.
Other than that, well, there are all sorts of pitfalls, and the best way to avoid them is to do lots of research and make sure you really understand what you’re doing before you do it. Always read all the instructions, and if they don’t make sense, read them again.
If you want to install a PV system yourself, buy from a supplier who can sell you the whole system. You can buy all the individual components online, sometimes cheaper, but it’s tough to assemble a system from scratch if you’re not a pro.