Markets with an existing network supply: parallel operation
The market development around renewable energies is very current and intensive. The focus of the most serious and professional activity lies almost exclusively on large industrial generators and the production of energy in large supply networks (grids) of industrial states. This is especially remarkable in the field of wind energy. The market of decentralized, small generators (off-grid) is still situated in the shadow of such activities: this also offers great potential.
The reduction of feed-in tariffs and the price reduction of the generators (especially photovoltaics and storage systems), as well as the increasing “power socket price” for electricity make the own consumption increasingly interesting.
The yearly development of the energy supply of “renewable energy” (summer – a lot of sun, winter – a lot of wind) support the idea of a continuous electricity generation by combining the sun and the wind as energy sources.
Upgrading existing photovoltaic generators, particularly single-family homes (in Germany approx. 5 GW) to self-sufficient supply systems. The reduction of photovoltaic installations in Germany offers established craft businesses the chance of using the existing infrastructure, distribution channels, customer access and service structures, in order to utilize the freed resources to their full capacity. The access to the distribution and installation capacities of such craft business can be achieved by means of associations, training events and the development of own support structures.
GRID-PARALLEL OPERATION OF AUTONOMOUS SMALL GENERATORS (ON-GRID)
- decentralization by means of small generators in parallel operation
- relieves the grid (generation according to consumption)
- makes the entire system more fault-resistant
- small generators in parallel operation are economically feasible even today, in case of own-consumption substitution (gridparity)
- the combination of photovoltaic and small wind generators compensates the seasonal fluctuations of the energy supply. In parallel operation, there is the possibility of extending the storage capacity to an economic size and the supply reliability is guaranteed by the grid.
Markets without supply networks: island solutions
ELECTRICITY SUPPLY AS AN “ISLAND SOLUTION”
- There is currently a worldwide, installed capacity of 22,5 GW (22.500.000 KW) supplied by diesel generators, of which more than two thirds in developing and emerging countries.
Island states and states with large surfaces have the highest installed capacities.
Most of the installed diesel energy systems are smaller than a MW.
- In Africa, with the exception of the states adjacent to the Mediterranean Sea and South Africa, less than 25% of the population have access to electricity. Similar circumstances can be found on the Indian subcontinent and in South-East Asia (Malaysia, Philippines, New Guinea).
- A cost-effective, reliable supply of electricity represents an essential infrastructure factor for the development and securing of the living standard of these people in these countries.
- Also, the majority of small, inhabited islands is supplied by diesel generators, although the sun and wind is present in ample supply, especially in these cases.
- Usual, commercially available diesel generators must be maintained at least twice a year or after 500 working hours (in case of a daily production of 6 hours, this means approx. 80 days), by specialized personnel. The availability and qualification of the maintenance personnel is a problem, especially in the areas where these generators are normally used.
- When compared to diesel generators, the power production by means of renewable energy generators (wind, photovoltaic, running water, surf energy in combination with energy storage systems) requires a lot less maintenance.
- While the electricity production costs are determined by the fuel costs and the maintenance effort, in case of the diesel generators, the electricity costs in case of renewable energy generators are mainly determined by the acquisition costs of the generator. As a result of decreasing costs of “renewable” generators, they are becoming increasingly economically feasible.