10.2.6 Biomass and Small Scale Renewables
Renewable sources of energy can provide energy in the final form required
by users while emitting significantly less GHGs than fossil fuels. Carbon emissions
are present through the use of fossil fuels during the process of planting,
harvesting and storage of the renewable resource and its transformation into
a commercial form of secondary energy.
Technology improvements in biomass productivity, harvesting and collection,
and conversion are expected to further reduce GHG emissions by:
- Increasing the yield of biomass forests and plantations;
- Gasifying biomass as an intermediate step for gas turbine based electricity
generation or cogeneration or other high efficiency combined cycle concepts;
- Converting ligno-cellulosic materials to ethanol for use as a motor fuel.
This is one of the few possibilities in the near term to displace fossil fuel
in the transportation sector because of existing distribution infrastructure
(Interlaboratory Working Group, 1997).
When regarding other small scale renewable technologies it is very important
to consider the historic technological improvements. Wind propelled electric
generators and photovoltaics have been able to reduce their cost for generating
electricity but costs are still relatively high as compared to small-scale hydroelectricity
and geothermal generation. These are options with lower unit costs, but for
which cost reduction potential is more difficult to identify. Technical feedback
and increasing economy of scale will lead to further cost reductions. Opportunities
for commercial-grid-connected wind and photovoltaic-based electricity production
systems will allow these technologies to be part of the large-scale renewables
framework, today primarily consisting of hydro and biomass based electricity
generation. Use of small-scale hydroelectricity and geothermal generation are
other options.
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