Renewable Energy Resources for Irrigation - Practices of Irrigation and On-farm Water Management - page 514

generally more benign than those of fossil. However, both biomass and geothermal
energy require wise management if they are to be used in a sustainable manner.
For all of the other renewables, almost any realistic rate of use would be likely to
approach their rate of replenishment by nature.
13.11.1.9 Transmission
If renewable and distributed generation were to become widespread, electric power
transmission and electricity distribution systems might no longer be the main dis-
tributors of electrical energy but would operate to balance the electricity needs of
local communities. Those with surplus energy would sell to areas needing “top
ups.” That is, network operation would require a shift from “passive management” -
where generators are hooked up and the system is operated to get electricity “down-
stream” to the consumer - to “active management,” wherein generators are spread
across a network and inputs and outputs need to be constantly monitored to ensure
proper balancing occurs within the system. Some governments and regulators are
moving to address this, though much remains to be done. One potential solution is
the increased use of active management of electricity transmission and distribution
networks. This will require significant changes in the way that such networks are
operated.
However, on a smaller scale, use of renewable energy produced on site reduces
burdens on electricity distribution systems. Current systems, while rarely econom-
ically efficient, have shown that an average household with an appropriately sized
solar panel array and energy storage system needs electricity from outside sources
for only a few hours per week. By matching electricity supply to end-use needs,
advocates of renewable energy and the soft energy path believe electricity systems
will become smaller and easier to manage, rather than the opposite.
13.11.2 Prospects/Future Potentials
In view of the increasing global climate concerns, interests in the development
and dissemination of renewable energy technologies have been revived/renewed.
Climate change concerns coupled with high oil prices, peak oil, and increasing gov-
ernment support are driving increasing renewable energy legislation, incentives, and
commercialization. European Union leaders reached an agreement in principle in
March 2007 that 20% of their nations' energy should be produced from renewable
fuels by 2020, as part of its drive to cut emissions of carbon dioxide, blamed in part
for global warming. Investment capital flowing into renewable energy climbed from
$80 billion in 2005 to a record $100 billion in 2006. This level of investment com-
bined with continuing increases each year has moved what once was considered
alternative energy to mainstream. Wind was the first to provide 1% of electric-
ity, but solar is not far behind. Some very large corporations such as BP, General
Electric, Sharp, and Royal Dutch Shell are investing in the renewable energy sector.