In my degree project I’m going to investigate a possibility of electric energy storage,
as an effective way of energy storage is still an unsolved problem. In this paper I will design a
small size pumped hydroelectric storage, and investigate its effects on the transmission grid.
In the first part I have chosen a concrete water tower, which was used to size and
create my models. After I had visited the site and took notes, I have created a threedimensional
CAD model of the physical structure, mainly based on measurements and
blueprints, but partly based on estimations. For further calculations this physical structure
model was used to obtain data, including volumes, heights and so on. Based on these data, I
have chosen all the devices that are required to convert the energy, and even the sacrificial
elements needed with it. After selecting all components, I could start creating the electric
model based on catalogues. The model I have obtained on this manner allowed me to run
various simulations to find out what effects such storage would have on the transmission grid,
and I could also designed a control circuit for it. So by the end of this part achieved a detailed
physical structure and electric model for further investigations.
In the next part some economical considerations were investigated. I have investigated
the investments costs, and all the other cost in connection with operation, and also looked at
the income side, where the expected gain is calculated. Based on these calculations I have
figured out the payback time, and checked weather it is marketable. This calculation was done
for single and multiple sight investments.
As a result I’ve found that under current national regulations, the payback time of the
investment is over ten years. It’s due to the financial support of renewable energy. But I’ve
also found that after the end of this support, this payback time will decrease to less than five
So my conclusion is that further investigations and a pilot project are suggested.