Your choices so far:
1 Water; 2 Electricity
| What is your resource? | What do you want to deliver? | What is the service the customer wants? |
| Biomass (digestible sludge) | District cooling | Comfortable indoor climate |
| Biomass (fermentable sludge) | District heating | Electricity |
| Biomass (solid) | 2 Electricity | Process cooling (< 0 °C) |
| Geothermal | Fuel: Gaseous | Process heat/steam (50 - 150 °C) |
| Sunshine | Fuel: Liquid | Process heat (150 - 1000 °C) |
| 1 Water | Fuel: Solid | Process heat (> 1000 °C) |
| Wind | Local cooling (ind. house) | Transport |
| Residual oils/fats etc | Local heating (ind. house) |
One main characteristic for traditional hydropower installations, with a dam, is that they are seasonal but at the same time they are controllable. The volume in the reservoir must be sufficient to accommodate the seasonal variations in precipitation.
With the ongoing climate change and the corresponding change not only in total precipitation but also in the distribution of precipitation over the year, several old hydropower dams will need a revision and the production pattern may need to be revised to avoid flooding. The planning of the water flow as well as the electricity production must both be constrained with respect to this. In many rivers, there are a number of power stations along the river flow and the control and the production in each single power station must be co-ordinated with all the other ones.
With submerged hydropower production, the actual production at any instant will be directly connected to the actual flow of water through the river. The water level in the river must be monitored so that there is always enough free height above the propellers for debris and for boats.
With a pumped power station, the electricity price will be the only determining factor for when to fill the reservoir and when to empty it.