How much heat will this DIY mirror give to your home

Added: 2026-05-24

[00:00:00][snorts] >> I have been experimenting with different types of mirrors for solar energy over the years, and perhaps my experience will help you better understand the capabilities of this system, which was made by one of the Dutch bloggers using 3D printing methods about a year ago.

[00:00:14]And it is obvious that these mirrors focus solar radiation on this receiver, which will be described in a minute.

[00:00:20]If you find many drawbacks to this mirror system, you may prefer these alternative options, and the internet will show you hundreds of similar solutions when you search for these terms.

[00:00:30]And for example, these mirror dishes are made in Afghanistan.

[00:00:34]This is another example that can be made on the basis of a satellite dish by each of you in less than an hour, and the receiver of this mirror dish was a kettle for boiling water or a saucepan for cooking food.

[00:00:46]This is another mirror dish, where the receiver is a Stirling engine, which converts the energy of solar radiation into rotation of an electric generator.

[00:00:55]That's why you understand that receivers can have different purposes. And let's take a look at this receiver of that Dutch mirror dish, where the solar radiation is focused on this metal plate and heats it up.

[00:01:06]Now you see the backside of that metal plate, and it is obvious that its hot metal will heat the water that circulates through the flexible pipe, and it could be water from the tank for hot water supply of a house.

[00:01:18]Many of you will notice the shortcomings of this receiver, and therefore I am now showing you two examples of professional receivers for heating water with focused solar radiation.

[00:01:29]In addition, it could be water of a swimming pool when the mirror dish is used instead of such solar pool water heaters, the heat from which allows the swimming season to begin several weeks earlier and finish several weeks later, and the summer temperature of the pool water will be several degrees higher.

[00:01:45]Also, it could be water from the pipes of a home heating system, and adding such a heat storage allows us to heat our house with solar energy not only during the day, but also at night.

[00:01:55]One of my older videos described a home heating project using mirror dishes in the central United States in the cold mountain town of Taos, and it turned out that the area of such mirrors should be 28 square meters so that they would give all the months of this heating season these kilowatt hours of heat, which completely cover these heating needs of a house with an area of 100 square meters.

[00:02:16]In addition, the difference between these columns gives us this excess solar heat, which can be spent on hot water supply and on heating a greenhouse or garage. And it is obvious that the heat production outside the heating season is used for hot water supply and pool heating.

[00:02:31]Unfortunately, winters in the Netherlands have several times fewer sunny days, and therefore this small mirror dish will provide the heating of a house with this amount of heat during three winter months, which creates a savings of 7 cubic meters of natural gas without taking into account the savings in November and March. If you think the savings will be much greater, then let's calculate together.

[00:02:54]The Dutch sun is low on the horizon in winter, and therefore its flux of radiation is only 700 W per square meter. And multiplying this value by the area of the mirrors and the cosines of the angles of incidence of the rays gives us this power of solar radiation that reaches all the mirrors of the dish in the middle of a sunny winter day.

[00:03:12]But the mirrors will only reflect 650 W because the reflectivity of household mirrors is usually poor for ultraviolet and infrared radiation, and the mirrors will also lose diffuse solar radiation.

[00:03:24]In addition, we will lose approximately another 100 W due to solar photons missing the receiver due to the fact that its metal plate is not perfectly black, and due to various heat losses, and therefore the water will only receive 550 W in the middle of a sunny day in January.

[00:03:41]Now I remind you that the mirror dish must constantly rotate to look at the sun, and therefore its heating power will change in this way from this sunrise to this sunset, and this is its maximum power of 550 watts at noon.

[00:03:55]All this heat production during one perfectly sunny day in mid-January amounts to approximately 3 and 1/2 kilowatt hours, and we must multiply this value by the number of sunny days.

[00:04:05]And this climate of the Netherlands tells us that it will be 5 sunny days in December, 7 days in January, and 7 days in February.

[00:04:13]That's why we get this level of the heat production during the three winter months, but it will be almost six times more in the summer because the summer months of the Netherlands have two times more sunny days. And this daily heat production will increase to approximately this situation due to the brighter summer sun and longer days.