A US report evaluates numerous factors to determine how western states can source 33% of their electricity from new renewable energy resources.
Increasing demand for renewable energy increases costs, as less economically attractive resources are required to meet higher targets, the report concludes.
Wind energy is found to be the largest contributor to meeting regional renewable energy demand when only resources from western resource hubs are considered, while contributions from geothermal, biomass and hydropower do not change significantly with increasing demand or changes to key assumptions.
Lawrence Berkeley National Laboratory produced Exploration of Resource & Transmission Expansion Decisions in the Western Renewable Energy Zone Initiative to examine, at a screening-level, the sensitivity of renewable resource selection, transmission expansion, and supply costs in meeting aggressive renewable energy targets to different assumptions and policy decisions.
Scenario of 33% from renewable sources
The report evaluates decisions under a number of alternative future scenarios centred on meeting 33% of the electrical load of western states with new renewable resources located within resource hubs identified in the Western Renewable Energy Zone (WREZ) Initiative.
Transmission investment costs are “substantial” at US$17-34 billion, but represent only 10-19% of the total renewable supply cost required to meet the 33% target, it concludes. Long transmission lines can be economically justified in particular cases, but the majority of transmission lines are found to be relatively short.
Key uncertainties can shift the balance between wind and solar in the renewable resource portfolio, and the costs of meeting renewable energy targets within the western states are heterogeneous without Renewable Energy Credits (RECs). Transmission expansion needs and overall costs can be reduced through the use of RECs, equating to an average savings of as much as US$6/MWh of renewable generation.
Tool compares economics of renewable enercy
Berkeley Lab worked with Black & Veatch to develop a new analytical tool to compare the economics of renewable resource areas for different load areas, and how different policies and uncertainties may affect resource selection and transmission expansion. The findings build upon the WREZ initiative that was managed by the Western Governors’ Association (WGA) and the US Department of Energy (DoE).
“We need better analytical tools like the WREZ model to enable private and public sector decision-makers to develop timely policies and make investment decisions that will prepare the region for a clean energy future,” says Montana governor Brian Schweitzer, Chairman of WGA.
“As a screening tool, we are not able to identify specific transmission lines or renewable projects that should be developed to meet a 33% renewable energy target, but we are able to identify important questions that need to be considered in more detailed models,” adds Andrew Mills of Berkeley Lab, one of the report authors.