Ice and slush are underfoot, occasionally the sun breaks through, and it's colder than a brass monkey's balls. When you finish work, all you look forward to is a bath full of hot water. But do you know that water can be efficiently heated by the sun even in the winter? And for free!
Water has a very high specific heat capacity (4182 J / kg / K) - which indicates the ability to store heat in itself. Water is approximately twice as good a heat accumulator as oil, eight times better than iron, and even thirty times better than lead!
Even a couple of years ago, water was heated by the energy of the sun only photothermic – using collectors that heat the liquid and then transferred the energy through a heat exchanger to heat water in a boiler.
The sun is unreliable. The sun is an excellent source of energy, inexhaustible in our foreseeable future, but it requires specific conditions. It’s not really the sun itself, but it’s our Earth that causes the unreliability of solar energy (due to weather, day/night, seasons), so overproduction of solar power needs to be stored. Fortunately, most of our homes are still connected to the electrical grid, so not relying entirely on storing power is quite easy.
Many people still see the energy produced by photovoltaic panels as "better, " and so it should be used to power some less ordinary appliances than a water heater.
