Environmental Engineering Reference
In-Depth Information
pacts through perennial crops. Its production and use is currently helping to create
international bioenergy markets, stimulated by policies to reduce carbon dioxide
emissions. Wind power in coastal and other windy regions is promising in the short
term as well. Other potentially attractive options include geothermal heat and elec-
tricity production, small hydropower, low-temperature solar heat production, and
solar electricity production in remote applications.
Substantial cost reductions can be achieved for most renewable energy tech-
nologies. Making these renewable energy sources competitive will require further
technological development and market deployment and an increase in production
capacities to mass-production levels.
A negative aspect of some renewables is that, unlike hydropower and geotherm-
al power sources, wind and solar thermal or electric sources are intermittent and
not fully predictable. Nevertheless, they can be important in rural areas where grid
extension is expensive. They can also contribute to grid-connected electricity sup-
plies in appropriate configurations; intermittent renewables can reliably provide
10-30% of total electricity supplies in an area covered by a sufficiently strong
transmission grid if operated in conjunction with hydropower or fuel-based power
generation. Emerging storage possibilities (like compressed-air energy storage)
and new strategies for operating grids offer promise that the role of intermittent
technologies can be extended much further. Alternatively, hydrogen may become
the medium for storing intermittently available energy production.
Because they are small in scale and modular, many renewable technologies are
good options for continued cost cutting. Cost reductions for manufactured goods
are typically rapid at first and then taper off as the industry matures.
