Solar Hot Water
Solar Heated Water, or solar thermal, collects the sun’s radiated warmth and stores it for our human uses. These systems work at raising water temperatures even on mostly cloudy days. You will still need back-up hot water heating if you desire hot water 365 days a year.
Solar domestic hot water systems consist of good sun exposure, water, collectors, storage tanks, copper pipe, and insulation at a minimum. Most systems for year-round homes in freezing climates also include small electric pumps, heat exchangers, system controllers, and glycol anti-freeze.
For summer season use the system can be as simple as a black metal tank or a black pipe on a hot roof, known as a Batch System. A step-up in performance and complexity is to marry the batch tank to a collector just below the tank and allow the water to thermosiphon into the top to the storage tank while the cold water, being denser and heavier flows down to the lower end connection of the sloping collector. This simple technology has been widely used for decades in mild climates. Most of these systems need to be drained any time you are worried about your tomatoes freezing.
For year-round use where you want to avoid the stress of worrying about bursting frozen pipes, there are many very nice options. These systems have evolved a lot since the 1970s when there was a spike in interest in renewable energy in North America.
Unless you are building or living off-grid, Oso Solar does not recommend installing solar hot water when solar electric options are available. Solar electric systems have ended up costing less for the energy you can harvest since about 2013. Solar thermal can still harvest more energy in a small space than photovoltaic. Four-season solar hot water also requires servicing on a regular basis while PV is usually maintenance free for many years.
Solar hot water can make sense for an off-grid home. Oso Solar still has a new single collector solar hot water system in stock since 2012 when the Natural Resources Canada grants ended and solar PV got cheaper. We will make a seriously great deal for someone that wants it!