Heating your commercial greenhouse with natural gas or propane in winters is understandable as the excuse could be given that it is required to keep the business going, but this excuse cannot be given if you have a greenhouse in your house because you wanted to have one. The cost of fuel to keep it working would be exorbitant.
However there is an alternate for this problem which is active solar systems and one of the benefits of active solar energy is greenhouse heating. Basically in active solar energy you can store the solar energy in the back up batteries which can be used later on when the sun is not shining.
To begin with, a homemade greenhouse is typically a lot smaller than the commercial operation. This would make it quite a difficult task to maintain the heat levels as the doors are opened many times and even for longer time periods, destroying the whole concept of keeping a greenhouse. Secondly, mostly homemade greenhouses are made of a single layer of plastic film. Because of this little lagging is provided, so when the sun goes down in the evening the temperature would instantaneously fall down and match the outside temperature, even at maximum it would be only a degree or two warmer.
There can be days when you do not get any sunlight because of the cloudy or rainy weather, the plastic layer would only protect plants from snow, wind or rain but it would not help it keeping the temperature warm, in fact the temperature would get really low.
One way to tackle this problem can be active solar systems. One of the several benefits of active solar energy is that it would let you use the sun heating at day time and will store energy for nights and even on the days when there isn’t enough sunlight with the help of back up batteries.
One thing that you could do is put in the ground of greenhouse walkways and plant beds, hot water piping, and then you must allow hot water to pass through it with the help of one or more than one solar panels. This will warm the floor and will make the soil a thermal battery which would keep the temperature of the greenhouse high all through night, or on days when the sun is not shining.
Well, these are the reasons of using active solar energy; however there are other benefits of active solar energy it can be used for domestic purposes, or in the areas where the availability of electricity from grid is not regular. Plus one of the most important reasons of enhancing it would be to completely banish the use of burned fossil fuels to make electricity, since this is the most reasonably priced and perfectly environment friendly device.
If you think solar power is expensive then think again and have a look at how to make solar panels at home.