Alternative Energy Creates Resilient Homes
Renewable energy, also called alternative energy, comes from natural sources: the sun (solar), the wind, rivers (hydroelectric) and the earth (geothermal). How can you best put these natural assets to work for you?
Production of electricity and hot water at home using natural energy from the sun is nothing new. But technologies have greatly improved over the past few years. Not only do they cost less to install, but they’re more reliable, more efficient—and simply a better deal.
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In addition, the supporting hardware is vastly superior to the old stuff. The politics of alternative energy is changing too, albeit more slowly than many would like. In many states, utilities are now required to buy back any “extra” electricity you produce. And both wind turbines and solar installations are eligible for 30 percent federal tax credits. Certain states and utilities also offer incentives. The real question now is not “if” but when you should make the leap to renewables at home.
Wind Turbines: Know Your Neighborhood
Small-scale wind turbines that create electricity have always been a fairly specialized form of power generation—most valuable in mountainous and coastal regions. The challenge has been to build a turbine that produces adequate electricity, even in low wind, to make it worth the cost.
We’re getting much closer. Along with the Automaxx, shown below, other small turbines now begin producing power in winds of just 8 miles per hour.
Because it “cuts in” at 5.6 mph wind velocity, the Automaxx 1500-watt windmill can serve a wide range of microclimates. Typically sold as a DIY package with charge controller, it retails for about $2700--roughly on par with similar capacity for a PV system, but keep in mind that solar doesn’t work at night, and windmills work whenever the wind blows.
The advantage of wind power over PV? The wind often blows when it’s dark outside. But before you buy, take a look at the national wind map published by the National Renewable Energy Laboratory (NREL). You’ll see that not every area of the United States is well suited for wind-powered living. In fact, if you live in any of the Southeast states—and you don’t have a place right on the water—wind is a long shot. You will make a lot more power with a good solar PV setup.
A perfect companion to solar panels and storage ,this ground source heat pump system uses the natural temperatures in the earth to do most of the heavy lifting. With variable speed loop pump and compressor, this WaterFurnace unit supplies heating and cooling at less than one-fourth the cost of high-end propane models.
Photovoltaics: Looking Sharp
A couple of years ago, photovoltaic panels crossed a threshold. As their performance increased, their cost-per-kilowatt decreased, putting them in parity with fossil fuels. In other words, solar power became as inexpensive to produce as gas or oil.
You now have a wide range of panels to choose from that can quickly boost your home power capacity. For example, JinkoSolar offers individual Cheetah panels that produce as much as 400 watts each.
Panasonic’s Evervolt EVPV360 can supply 360 watts. This means that they take up less real estate on your roof or in your yard. This is something to consider, especially if only part of your property gets full sun most of the day.
Another way to optimize your solar potential is to install some of the new bifacial panels. These panels, which are just hitting the market, achieve even more performance, because they collect and convert sunlight on both sides, including reflected light.
You may also be aware of solar panels that look like roof shingles. These fell out of favor for a while, but have returned. Both GAF Energy and Tesla have recently launched new product lines of so-called “building integrated photovoltaics.”
The Energy Shingle (ES) integrates solar technology into existing roofing processes and materials. It can be nailed like a regular asphalt shingle, and is less than a quarter-inch thick. It integrates neatly with traditional shingles, to create a sleek and attractive look. www.gaf.com
One of the key improvements in BIPV in recent years has been the way they connect to each other and your home’s power system. The early products were co-dependent. In other words, when the connection broke on a solar shingle, the whole roof stopped producing.
Newer systems have built-in redundancy in their wiring, and most are more modular, making replacement of a single faulty tile or panel less of a hassle. Monitoring tools also have improved dramatically. You can now check on your solar performance using an App such as SolarEdge on your smartphone. This not only helps you plan power use; it can alert you to problems.
Is it better to lease or purchase a solar system? This often depends on your tax bracket. If you are unable to take advantage of the 30 percent federal tax credit, a third-party-owned system might be the way to go, as the solar provider can utilize the tax credit and pass on the savings.
Solar leasing programs are not available in every state (or in every region of a given state); however, the largest providers are continually expanding their territories. Some of the companies that offer solar leases are SolarCity (owned by Tesla), SunPower, SunRun and Sungevity.
Scalable Battery Storage. JinkoSolar’s Eagle RS battery storage includes an automatic transfer function that kicks your home over into battery mode in a power outage. The high-capacity batteries can crank out 7.6 Kilowatts, and supply 26.2 kilowatt hours of energy at full charge.
Solar Hot Water: Smart Storage
The availability of extremely durable hot water storage tanks—which in some cases also serve as water heaters—has made solar hot water collection even more viable. Many tanks now include a separate closed loop of a freeze-resistant liquid. That extra loop is specifically for solar hot water—so that when the sun is shining, the solar panels on the roof heat the clean water in the tank.
But when the sun is not sufficient (or you have teenagers using up the “free” hot water) an external boiler or heating system built into the tank kicks on to make up the difference.
One of the great advantages of a solar hot water system is the relatively rapid payback. In other words, if you install this year, it may pay for itself in less than three years, especially once you figure in the tax credits and rebates available.
Resilience: Back-Up Plan
A renewable energy system can be part of a strategy for keeping your home powered up during storms and power outages. Grid-tied solar PV systems aren’t available when the grid powers down, so it’s necessary to have a back-up plan.
While gas- or propane-fired generators have been a reliable source of back-up power, their reliance on fossil fuels means they will eventually be phased out. Solar- and wind-powered backups are becoming cost competitive with these outdated products.
Also, innovations keep coming. For example, stand-alone solar panels can be used to power specific appliances. Or you can install a small battery backup that runs only the critical life systems in your home when the power goes out.
This hybrid inverter from Schneider Electric automatically switches your solar panel power from grid-tied to battery backup automatically in a power outage. The XW Pro can output up to 12 kW at peak, 8.5 kW continuous power. It charges batteries quickly, at 48Vdc, 120/240Vac.
Another rising trend also factors in: Electric vehicles. They contain large, powerful batteries. If tied in to your home’s electrical system, they can provide backup power for days. The new Ford Lightning electric pickup truck, for example, boasts about this capability. In this way, different power sources become part of a dynamic system that not only makes your home more resilient, but turns it into a dynamic participant in the grid, rather than just an end user.
Q: Can I run my house directly from solar with no battery and not connect to the grid?
Not really. Solar energy tends to be collected unevenly, as clouds pass or the sun’s angle shifts. Electronics don’t like ups and downs. A battery, however, “smooths out” the energy to make it more accessible.
Q: Do I need to wash my solar panels a lot?
No. Research shows that unless they’re extremely dusty and dirty, cleaning doesn’t improve panel performance much.
Q: Can solar panels handle hail storms?
Yes, but make sure they are made with heat tempered glass. Some panel makers cut corners, and you could pay the price.
Glossary of Terms: Know the Lingo
- Inverter: Device that converts direct current (DC) electricity into alternating current (AC), the type of power most commonly used by U.S. appliances and light fixtures.
- Grid-Tied: Electricity produced on site (from photovoltaic panels, wind turbines, etc.) is fed directly into local power lines, rather than being stored in batteries.
- Cogeneration: Production of electricity from heat that would otherwise be wasted, such as hot flue gases produced by a gas-powered furnace or boiler.
- Wind Maps: Useful for siting (and evaluating the viability of) wind turbines, wind maps show how much wind can be expected in a geographic region or specific site.
- Building Integrated Photovoltaics (BIPV): Electricity generating solar panels that have been designed to resemble various familiar types of roofing.
- Standby Heat Loss: Heat lost by hot water that is sitting passively in a storage tank or pipes. Super-insulated hot water tanks greatly reduce this loss.
Publisher’s Note: This content is made possible by our Today’s Homeowner Campaign Sponsors: Whirlpool, Carrier and Jinko Solar. These companies take sustainability seriously, in both their products and their operations. Learn more about building and buying homes that are more affordable and less resource intensive.