Can you, during the day when the sun is shining and therefore the solar panels produce a lot of electricity, instead of sending this electricity to the grid, run a motor that pulls a large weight upwards and then, when there is no sun, let it come down and generate the energy? use the released to make electricity?
Answer
Hello,
Indeed, you could buffer energy in this way during the day and also make electricity later in this way. We call this a ‘savings electricity plant’
However, depending on the amount of energy you would need a large weight and a very large installation, in relation to the energy supplied. In addition, the efficiency of such an installation is relatively small (motor losses, mechanical losses, …). This installation would be expensive and would require a lot of maintenance.
What is comparable and is used in reality is an energy buffer via water. When there is a surplus of energy, water is pumped into a large reservoir and later electricity is produced again via the principle of a hydroelectric power station (water flows downwards and makes a generator run). Such an installation is feasible in price and feasible in realization … a water reservoir is easy to build, just use a natural lake somewhere and build a dam.
So compared to the idea of ​​pulling up and lowering a large weight, you would need a weight in the order of the volume of water… even if it were 7.8 times less in volume (specific gravity of iron is 7.8 x larger than water), you can still imagine how large the weight should be in volume…
There is one in Belgium reservoir power station near Coo and Trois-Points near Liège.
Oh yes, the advantage of such a plant is that it can start up in a short time and can therefore really be used as a buffer if there is suddenly too little electricity. See http://nl.wikipedia.org/wiki/Coo-Trois-Ponts for more information about this ‘savings power station’.
Answered by
ing. Rick Hostyn
Electronics ICT
Doorniksesteenweg 145 8500 Kortrijk
http://www.vives.be
.