When people start to consider becoming grid-independent, it’s understandable that they start off by looking at solar panels, batteries, and other components of the solar power system itself.
The thing is, building a working independent solar system for your home is about more than just slapping as many solar panels on your roof as will fit. The other half of the equation is about how much energy your home consumes. We might not think much about things like ovens and washing machines as sexy, hi-tech purchases. The truth, however, is that companies have been working constantly on getting appliances to do the same work for less electricity. The more efficient the appliance, the less power you have to create in the first place.
In some cases it might work out better to replace your most energy-hungry appliances with new ones instead of buying enough solar energy to cover your old power hogs. If your appliances are getting on a bit, this might be you. But if you have fairly new devices then it’s not such a pressing issue. That being said, as your appliances reach their end of life you should make good decisions on what to replace them with, in order to put less pressure on your existing solar power system.
Lighting the Way
The invention of the electric light changed the world. First of all, it made light less expensive. Since candles and oil lanterns were way too costly, people went to bed early. With convenient and safe electric lights, people were more productive.
Unfortunately, the incandescent bulbs that we’ve used for the majority of electric light’s history aren’t very efficient at all. They work by putting electricity through highly resistant filaments that then heat up. Incandescent bulbs are so inefficient that the light they give off is almost an afterthought. Typically only about 2% of the power that goes into one of these bulbs is converted into light. The rest is all wasted as heat, which also leads to the bulb’s failure in the long run.
Later, fluorescent bulbs came along, often marketed as “energy savers”. These bulbs are much more efficient and generally use only 25-33% of the power incandescents do. They are also pretty cheap these days, and it’s easy to replace your existing bulbs with them. The main downside is environmental. These lights contain mercury and other harmful chemicals that don’t play well when thrown in the trash. They are also pretty fragile.
I think the clear winner here has to be the latest LED lights. They are much more efficient than traditional lamps AND incandescent energy savers. The prices on these lights have come down dramatically; in the USA they will soon be the most common type of light.
LEDs make almost no heat and last much longer than other technologies. Traditional bulbs may last up to 1000 hours and fluorescent bulbs as much as 8000 hours. LED lamps last more than 30,000 hours as long as they operate within their specified temperature range. If the LED gets hotter than it should for some reason, then its lifespan will be less. Even then, it’s going to likely outlast all other options. In terms of energy efficiency, nothing beats LED in the consumer market at the moment. I bought some LED bulbs recently for literally a few bucks. They were rated equivalent to a 60W tungsten incandescent, with a power draw of 4W. You do the math.
One of the biggest energy hogs in every home is the water heater – the device that provides hot water for showers and any other use you want to put heated H20 to. The amount of power that a water heater needs will put quite a dent in your total solar energy budget.
The good news is that you don’t have to get a water heater that needs electricity in the first place. There are alternatives such as using natural gas. When it comes to solar energy mixes where heating is involved, you’ll find that gas comes into the conversation quite a lot. Whether you care about the environment or simply about being grid-independent, gas is a viable option.
Of course, gas does not make you as independent as many would like. After all, you need to get the gas from somewhere. It’s either going to be bought by the tank or get piped to your home through infrastructure.
But wait! It turns out that you can power your water heating with solar energy. You just don’t convert it to electricity first. Instead, you use a solar water heater which heats the water directly and then stores it for your later use.
Solar water heaters are actually rather complex machines and there are various designs. I discuss them at some length in another article, but all you have to know right now is that there are independent solar options to getting a hot shower that will keep you truly off the grid.
As I said above, whenever we are talking about heating things, the power requirements go up significantly. Since cooking involves making things very hot so that they don’t end up killing you with bacteria, you can imagine that it pulls a fair amount of wattage.
Once again, the most cost-effective solution is to switch to a gas oven and stove top. And once again, this means that you aren’t really independent. If you only care about eco-friendliness then this doesn’t really matter, since the gas used in these stoves is green.
If you don’t like the idea of being dependent, then your only real option is to use an electric cooking device and run it from your solar power setup. The good news is that you can get some very energy-efficient ovens and stovetops these days. Simply look at their power requirements and calculate that into your solar setup to make sure the system can handle the load.
There are a few tips I’ve found when it comes to choosing cooking appliances that use less power. Self-cleaning ovens, for example, tend to be more energy efficient because they have better insulation and therefore lose less heat. Likewise, convection ovens use 20 percent less power than regular ovens. There’s a neat tip for stovetops too. Although they can be expensive, induction stovetops are very energy efficient. You need compatible pots, but these stovetops use electrical induction to heat the cookware, so the actual stovetop itself doesn’t get hot. It’s much more efficient and very cool.
There’s a third option, but it does require that you go outdoors for it to work. They’re known as solar ovens, and they have found a niche in the camping world as well as in third-world nations that do not enjoy widespread electricity. These devices use collected solar energy to cook food and are amazingly effective thanks to improvements in manufacturing. As long as you are willing to adapt your lifestyle a bit and cook some meals outside, then they can be an important part of the energy mix in your home.
Fridges and Freezers
If you thought that heating things up requires a lot of power, wait until you have to cool things down. This can also be a real power hog, especially if you live in a hot climate. This is not an optional extra in the way that air conditioning might be. If you don’t keep your food cold, you’ll literally die from some terrible food poisoning.
There’s a whole new generation of energy-efficient fridges and freezers. Appliances these days will list their monthly or annual power consumption in kilowatt hours. All you need to do is choose something that will fit comfortably in your kWh budget. It’s generally better to opt for smaller units, since they consume less power. Changing your diet to include less frozen food will end up being better for your health, although more expensive. You’ll have to balance these different competing issues.
Air conditioning is one of those things that we have traditionally been told we have to give up when it comes to running a home on solar power. When you think about it, that’s a little ironic. The best places to use solar power are hot, sunny locations; exactly the sort of places where you want air conditioning.
The good news is that you can now have air conditioning using solar power. This is mainly thanks to air conditioners themselves getting more power efficient; meeting better solar panel technology halfway. They will still put significant pressure on your power reserves, especially overnight, but are practical if you live in a climate that warrants it.
You should also know that there are other ways to use air conditioners with solar power than to plug an all-electric unit into your home solar setup. There are now hybrid solar air conditioners that combine a PV panel and a specialized solar collector to do the job. The sun heats the refrigerant directly, which means you only need a low-power compressor to drive the air conditioner. These products are known specifically as solar air conditioners and are an independent system from your other solar power gear.
That covers cooling needs in summer, but what about winter? The good news is that solar air conditioners can also heat your home in winter. Running traditional electric heaters is impractical unless you are willing to pay for that sort of solar capacity. Gas is always an option, but once again makes you dependent.
Whatever source of heat you choose, the most important thing to ensure is that your home has good insulation. This reduces how much heating you need and thus the energy cost, since you aren’t pouring heat into a leaky home.
Generally Efficient Appliances
Given how cheap grid power is, most of us don’t really bother to look at things like power consumption. On grid-based energy, an extra kWh here and there makes a small blip on your bill. When you are providing all that power out of your own pocket with solar energy, then it becomes much more important.
Thanks to overall increases in environmental consciousness by manufacturers, all appliance makers will list how much energy their products require. All you have to do is look at those figures and see if they’ll fit into your energy budget. I’m not saying that you should always pick the appliance with the lowest energy use. You have to balance it with performance and your personal needs. Plenty of energy-efficient appliances aren’t that thrifty because of clever design so much as because they suck at what they do!
In the end, if you can pick the right appliances you’ll be much closer to a harmonious solar setup that’s balanced just right.