Solar Power - How much do you really need?

Let’s face it – solar panels are expensive! Although the price per watt has gone down significantly over the past 5-10 years, it still can put a huge dent in your budget.

So how much solar power do you need, really? Every household is different, so there is no set answer. You will need to ask yourself a set of questions and make some decisions before you can determine your need.

How many people are living in your house? The more people you have, the more power you will need. When our kids were little, they didn’t use electronics and my husband and I shared a computer. We only used our computer during the intense sunlight hours of the day, a two-way radio on occasion and a few lights at night. That was all we needed to power. We live in the tropics, so there is no need for heating our house. We washed our clothes by hand and hung our clothes out to dry, so no need for a washing machine or dryer. But, everyone’s lifestyle is different!

What appliances are you just not willing to live without? Are there alternative ways of running those appliances besides using electricity? Would using propane or kerosene for your range, oven, fridge and even your dryer and heater be an option for you? Of course you would still need electricity for your dryer and to heat your home, but not near as much if it is using propane. And if a purchased fuel is out of the question, is it possible to use wood to cook and heat with? Any appliance you use that involves a heating element is going to drain your solar ‘bank’* in a hurry. So considering as many alternatives as possible will really help conserve your electrical usage, and ultimately, the number of solar panels you will need.

How many gadgets do you plan on using? Computers, tablets, phones, games… the list can get pretty long! Can you do without that tablet, if your phone can pretty much do everything the tablet does? What type of computer do you have? How much power does it take to run? On a laptop, you can look at the cord’s brick and it tells you what the volts and amps are. The more volts and amps the more powerful the computer, but also the more power it will pull from your solar bank. And to translate that into watts: volts x amps = watts. So, the brick on your computer’s cord says “Output 19V — 4.74A”, for example, then that computer uses around 90 watts while it is plugged in and on. It will use less when it is just plugged in charging the battery with the computer itself turned off. This is what we often do.

How big is your home? How many lights will you have? Is your home bright enough during the day so that no lights will be needed during daylight hours? What kind of lights do you have? How many watts are they pulling? LED lights pull a lot less power than even fluorescent lights.

Look around your house and take a detailed tour. What do you use that involves power? What do the others in your household use? Make a list and decide, as a family/group: what things you all can do without, what things can be powered by an alternative power source and what things will absolutely need to stay. The more things you can put in the first two lists the better, especially those things that use a lot of wattage. Then look at your power bills and see what your household usage has been over the last year. If you determined you could do without a few high wattage appliances, then you can lower whatever your average usage has been.

For example, a typical US household of four uses around 900 Kwh/month. With that amount of usage, you would need around 35 200-watt solar panels. If you can get this down to say 500 Kwh/month, you will need around 20 200-watt solar panels. This would mean a huge savings! This is an estimation only. Contact a qualified solar systems installer for more precise numbers.

Some people run a “split system”, part solar and part grid power. This would allow you to slowly move toward being off the grid, and to learn the ropes of solar power with a smaller budget. A few solar panels would allow you to go grid free at night with your lighting. Want to try this on your own just to see what it is like? You will need a solar power kit and some 12 volt LED lights.

Once you do go off grid, to eliminate frustration, you will want to make sure you have enough solar energy in your system. If you don’t, you will be fighting over who gets to plug in their computer next, and have many a candlelight evening! Not because you want a romantic date, but because you ran out of power and have no other choice. Believe me, we’ve been there numerous times!

Hopefully this article has helped you. Let us know how it goes with your endeavors to go solar.

*A solar ‘bank’ is the energy stored up in batteries. The solar panels charge up large batteries, which allow you to have electricity whether the sun is shining on the solar panels or not. Therefore, during the day, more electricity can be used because the solar panels are keeping the batteries charged even while you are using power, assuming you are not using more power than your system can maintain.