New Energy Watch

Do-It-Yourself Solar Sources

There's the sun blazing away, and here you are on the ground, and away goes all that unharnessed energy again. You're interested in solar panels, or in heating your water with solar, or in optimizing your house for passive solar heating, or all of the above. But the hunt for information takes a lot of time and bookmarks, especially if you're inclined to do the initial research yourself and stay hands-on throughout the project.

Here's an excellent collection of research links from BuildItSolar.com, covering the following topics:

• General Engineering Reference Sites
• Software Tool Lists
• Solar Position and Radiation Tools
• Windows and Glass
• Home Heat Loss/Gain and Passive Solar Home Design Software
• Energy Savings Calculators
• Solar Collector Design
• Piping and Plumbing Analysis and Properties
• Heat Exchangers
• Pumps and Solar Pumping
• HVAC
• Refrigeration
• Electrical
• Electric Motor Current Draw
• Unit Conversion
• Heat Transfer Analysis Methods
• Materials Specs
• Pollution and Emissions Calculators
• Energy Conversion
• Books and Publications

Even if you just want to hire an installer or contractor, you should educate yourself on the topic to get the most out of your new solar power.

To find reliable solar installers in your area, consult FindSolar.com.

~ Doug Logan, NewEnergyWatch

A Simple Solar Panel

There are some great  statistics about the amount of energy we could harvest from the sun if we were able to harness solar power efficiently and on a wide-scale basis. As the National Renewable Energy Lab  reports, “Every day, more energy falls on the U.S. than we use in an entire year.” An interesting point, and doubly interesting when considered in relation to another NREL factoid: “Every day  more solar energy falls to the Earth than the total amount of energy the planet's 5.9 billion inhabitants would consume in 27 years.” (That tells us something about the disproportionate use of energy in the U.S. Granted, we get a lot done with that energy, but we also waste enormous amounts of it.)   

Solar power is clean, quiet, and surprisingly inexpensive after clean-energy rebates have been reaped and the remaining cost of equipment has been amortized. A lot of us aren’t in a position, either physically or financially, where we can do much with solar power. On the other hand, a lot of us are perfectly solar-capable, but the notion of “going solar” is daunting in terms of research, paperwork, initial investment, construction hassles, and so on. So we do nothing.

Well, it doesn’t have to be all or nothing. You can get involved in solar energy in a meaningful way for about $300. In other posts we describe deep-cycle batteries that store energy derived from the sun,  and inverters that turn 12-volt DC power into AC.

The heart of the system is the solar panel. For less than  $150 you can get a small, plug-and-play panel with an output of 15-18 watts, giving a current flow of a bit over one ampere (at 12 volts). With a decent amount of sunlight, that’s enough to keep a 12-volt deep-cycle battery topped up between regular discharges of, say, 8 to 10 amp-hours. At least that’s been our experience over about eight years of experimentation with just such a system. See our 12-Volt Basics post for more information on watts, volts, and amps.

With that amount of replenishment available, you can do a host of small electrical chores, including running lights, making your morning coffee, and recharging power tools and hand-held vacuum cleaners. This accomplishes two things. First, it gets you familiar with solar energy combined with 12-volt DC power. Second, it takes a fraction of the load off the power grid. When millions of people contribute a bit, day after day, big things happen.

For solid information on how photovoltaics work, visit the U.S. Department of Energy’s Photovoltaics Basics page.

For a review of a small panel we can recommend, see Product Review: ICP Sunsei Solarcharger 1200.

~ Doug Logan, New Energy Watch

Product Review: ICP Sunsei Solarcharger 1200

For most of our experiments with trickle-charging and maintaining batteries over the years we’ve used a simple 15-watt panel from ICP Solar,  usually in conjunction with a charge controller, but often by just keeping an eye on things and a multimeter handy. That panel has withstood baking sun, snow and ice, scratches, drops, short-circuits, and even a fracture of the glass in the back of the case (from being stepped on). It’s still going strong. Meanwhile, ICP has put out a updated panel under the Sunsei brand name, an 18-watt module called the Solarcharger 1200. We ordered one and have had it outside the workshop for a while, topping up a battery used for various chores, including recharging other batteries and running a small TV. We also ordered the optional but highly recommended Sunsei charge controller, so that we can more or less forget about monitoring the battery.

While the glass area of the panel seems about the same as its predecessor, it’s better protected on the new model, and ICP has made big progress with weatherproofing, connectors, and accessories. Shown in the photo here is a “what’s in the box” selection that came with the Solarcharger 1200. From left to right, 1) 10-foot extension power cable with male and end connections, 2) 1.5-foot connector with O-terminals, 3) 1.5-foot connector with female 12-volt socket., 4) 1.5-foot connector with male 12-volt plug, 5) 1.5-foot connector with heavy-duty battery clamps, 6) double-ended cable to connect two panels together 7) connector with bare wires for connecting to charge controller. At bottom is the supplied mounting hardware.

We can recommend this panel for several reasons. First, it does what it’s supposed to do. (Whether it can survive the trials and tribulations suffered by its forebear remains to be seen.) More importantly, it’s completely simple to set up. The ICP engineers have done a great job of making the whole process --  including the ability to add more panels and greater capacity -- completely plug-and-play. There's also a 10-year warranty on the product.

For those who don't even want to contemplate wiring a charge controller between the panel and the battery, ICP makes the same panel in Model 1201, which has an integral charge controller. We haven't tested that one. The links below are to the Model 1200 (note that the Amazon photo is wrong and there's a typo in the headline -- "120-volt" instead of "12-volt") and the optional Sunsei charge controller, which can handle up to a 10-amp current.

Simple 12-Volt Solar: Every kWh Counts

With a few bits and pieces -- a battery, a solar panel and charge controller, and either a 12-volt socket (cigarette lighter adaptor) or an inverter to change DC power into AC -- you can get involved with solar energy in a basic, inexpensive way, and gather enough energy from the sun to power quite a few small appliances, as well as recharge batteries that run everything from vacuum cleaners to power drills and flashlights.

Every watt of energy saved helps break our disgraceful dependence on OPEC (for a quarter to a fifth of our daily oil needs). What helps the most is developing the habit of looking for ways to conserve, and using alternative sources of power whenever possible. Running most of your handheld power tools on energy gathered from the sun is a great way to start. And it’s fun.

Most of us who run boats and RVs, and who tinker a bit under the hoods of our cars, are familiar with 12-volt batteries, at least the type used to start engines, as opposed to deep-cycle 12-volt batteries, which are designed and built somewhat differently, and for different purposes. If you’re new to 12-volt systems, read 12-Volt DC Basics, then 12-Volt Safety Issues. After that, if you’re interested in getting involved, read more fundamentals in the other posts in our 12-Volt Power category. If you're not a tinkerer, and would prefer to jump into solar power with both feet, consult www.findsolar.com for professional installers in your area.

Doug Logan, New Energy Watch

Turning carbon dioxide into fuel -- with solar power

Clifford Kubiak, professor of chemistry and biochemistry at UC San Diego, has made a prototype device that uses solar energy to split carbon dioxide into separate components of oxygen and carbon monoxide. Carbon monoxide is a poison, but it's also needed in many industrial processes, and more importantly it can be made into a liquid fuel. This isn't a new concept; it was studied during the last big fuel crisis in the '70s, but abandoned when the crisis eased. This time it's not only important for economics but because of the environmental crisis. The carbon dioxide load must be dramatically reduced, while alternative fuels need to be ramped up.

Professor Kubiak's device can't yet produce enough power from sunlight alone to sustain the process of splitting up the CO2, but with some tinkering, mostly with the material used to make a crucial semiconductor, there's great promise. Here's the full press release from UC Dan Diego.

Finding solar installation answers and installers

Sometimes it's hard to know where to get started. Here's a website that gives good basic information on home solar installations, and provides links to local pros who can do the job. It also has a really good online cost estimator that takes into account your locale, utility company, current electrical usage, and factors in available breaks and rebates.

www.findsolar.com/

What are your experiences with home solar installations, pro or con?

~ Doug Logan, New Energy Watch