Abstract:
As part of the transition to a ‘low carbon economy', renewable technologies are
expected toplay an increasing role in reducing dependence on fossil fuels for
energy and electricity. Windpower in particular is likely to become a much
larger contributor to the UK's energy mix. Thecurrent dominant design for large,
grid-connected wind turbines is a three blade rotor with ahorizontal rotating
axis. The concept of a vertical axis wind turbine (VAWT) is relatively new,
buthas several advantages over horizontal axis alternatives. It is able to
capture the wind from anydirection, and the vertical axis is such that the rotor
equipment is located at base level, makingit is simpler and less costly to
install and maintain.
The Energy Technologies Institute (ETI) is a UK-based company formed from global
industriesand the UK government. One of three projects looking at new turbine
design and concepts foroffshore wind is the Novel Offshore Vertical Axis (NOVA)
project, a UK-based consortiumlaunched in January 2009 to look at the
feasibility of a NOVA turbine.
achieved through the installation of NOVA wind turbines, in comparison to
conventionalhorizontal axis wind turbines (HAWTs) for offshore power generation.
The increased powerrating of the NOVA turbines compared to current HAWTs is
expected to provide considerablereductions in lifetime greenhouse gas emissions.
It compared the emissions from 1 GWinstallations over 20 years, based on a life
cycle analysis of construction, operation anddisposal. The comparison used the
popular Vestas V90 3 MW model and the proposed NOVA10 MW units.
The estimated lifetime emissions were 521 kt CO2e for the conventional design
and419 kt CO2e for NOVA. Using budget share to attribute the reductions to the
project partners,Cranfield's brainprint was 34 kt CO2e.
As there are no current NOVA units in operation, there were high uncertainties
associated withthe estimates. A Monte-Carlo simulation resulted in a mean
difference in emissions betweenthe two installations of 102 kt CO2e, with a
standard deviation of 108.