When it comes to renewable energy, nothing gets more press than solar power; and for good reason. The sun is out there all day, every day. Even on cloudy days, the sun is showering us with energy that can be harnessed and used to heat our homes, power our appliances, and replace the expensive, fossil fuel burning energy companies.
Every square meter of sunlight carries 1,000 watts of energy – a massive burst of raw power. But, is solar power really an efficient option, and if so, is it affordable? Let’s take a closer look at what energy costs in your home can be replaced with solar and how effective they generally are.
Solar Hot Water and Space Heating
Solar hot water and space heating is one of the simplest ways to harness the power of the sun. It requires a solar collector, a tank on your roof, and the necessary connections to circulate heated water throughout your home. It’s about 80% cheaper than installing solar panels and can pay for itself within 2-3 years instead of 20.
What You Need for Solar Heating
There are two different types of solar heating installations – a passive installation that circulates water directly from the solar collector throughout your home without any pumps or motors, and an active installation that pumps cold water into the collector and hot water into your hot water tank where it can be stored for later use. The simplest to install and least expensive is a passive system because it requires fewer parts, less maintenance and no permits. However, you should still be careful when installing a passive solar hot water system, if only because you’re working with active pipes in your home.
Types of Solar Collectors
A solar collector is a panel attached to your roof that will absorb energy from the sun and convert it to heat. In the case of a passive system, the collector will directly heat the water in a tank attached to your roof. Basically, it’s like a greenhouse for your home’s hot water.
However, not every home can benefit from a simple, flat plate solar collector. In colder climates where that water might freeze, you will need a more indirect system. In this case, you will need an evacuated tube system. What evacuated tubes do is surround the water pipes with glass tubes that have inert air in them. This counteracts the ambient air temperature so only the sun’s energy affects the overall temperature.
Additionally, those pipes will usually contain some kind of coolant rather than water. The heated coolant is then transferred to a separate water tank to heat potable water. The water never freezes, the pipes stay strong, and you have hot water even in the winter.
Putting in a solar hot water system starts with analysis of your hot water needs. How much do you use and what do you currently pay for it? Likely, you will never be able to replace your entire hot water supply with solar hot water, but anything you do now will help your bills in the future.
Beyond the solar collector – which will be between 4 and 12 feet long – you’ll need the following parts to complete a solar heating installation:
• Storage Tanks – For active systems using evacuated tubes, storage tanks will hold the potable water away from the roof. This allows you to heat the water in a separate location more safely in cold temperatures.
• Water Heater – If you choose to remain connected to the grid, with the option for outside energy to heat your water, this is important. Most people remain connected to be sure they never run out of hot water. If the solar tank drains when you have company or it gets too cold outside, this will be welcome.
• Heat Exchanger – If you are using coolant in your solar collectors, you’ll need pipes or coils to transfer the heat from the coolant to your water, usually inside your storage tanks.
• Water Pumps – In an active system, you’ll need water pumps to move water to and from your solar collectors. Passive systems don’t use water pumps.
• Valves and Controls – These are used in active systems as well. Controls will determine where water is pumped and when to turn on your hot water tank. You can also install an isolation valve to cut off your solar system if something goes wrong along with a tempering valve. If you’re using direct hot water from your solar collector, a tempering valve will make sure it doesn’t get too hot when you’re in the shower or washing dishes.