California’s Future Grid Could Support Deep GHG Emissions Reductions

Energy storage and demand response are among the keys to achieving California’s long-term greenhouse gas emission goals.
Published: Tue 30 Sep 2014

The results from the first phase of the National Renewable Energy Laboratory’s (NREL) modelling of a future grid for California reveal that a greenhouse gas (GHG) emissions reduction of more than 50% below 2012 levels can be achieved by 2030 with minimal rate impact, minimal curtailment to renewables, and without compromising reliability.

50% GHG emission reduction target

The California 2030 Low Carbon Grid Study (LCGS) is focused on exploring how the California electric sector can cost-effectively support deep reductions in GHG emissions. The phase 1 study models two low-carbon portfolios that were developed to meet a 50% GHG reduction target by 2030. This target was identified as necessary to be on track to meet the 2050 target of 80% below 1990 levels (required under Executive order S-3-05).

Other key assumptions included a wide range of renewable generation and energy storage, increased flexibility and strategic use of gas-fired generation, coordination with Western Electric Coordinating Council (WECC) balancing authorities and energy imbalance market(s), and the use of energy efficiency, price-responsive demand, and dispatchable load.

The ‘Target Case’ of 177TWh zero-carbon energy achieves 58% emissions reduction below 2012 levels, while the ‘Accelerated Case’ of 205TWh zero-carbon energy achieves 72% emissions reduction below 2012 levels. For comparison, the ‘Baseline Case’ (maintaining 33%

Renewables Portfolio Standard compliance) of 110TWh zero-carbon energy achieves 18% emissions reduction below 2012.

Energy storage and demand response provide load shifting

Other key results:

● The production cost savings from reduction in fossil fuel purchases for the target case are US$5.5 billion, while the costs of the investment in a low-carbon portfolio are US$5.3 billion, resulting in a saving of US$0.6/MWh and thus minimal rate impact on rates.

● Short-term system flexibility and regulation was served primarily by imports, exports, demand response, dispatchable hydro and energy storage. This frees up the natural gas fleet to serve primarily as block-loaded intermediate generation.

● In 2030, regional trading was mostly renewable, rather than carbon-intensive fossil energy. Annual import quantity was roughly half of today, but import patterns and regional flows were not drastically different.

In an information sheet the NREL states the LCGS to be unique in its focus on emissions reduction, and in its use of a diverse set of resources and portfolio-balancing measures aimed at achieving a cost-sensitive, low-carbon grid without major disruption to transmission flows or trading patterns.

“The findings are significant because they illustrate an affordable, reliable, and practical trajectory toward meeting California’s ambitious 2050 GHG emissions goals.”

Phase 2 of LCGS

Phase 2 of the study is now under way and will include an independent rate-impact analysis and the running of further scenarios and sensitivities to identify additional ways of reducing costs and increasing efficiencies.

With GHG emissions reduction in the power sector a focus of the Obama administration, the focus will likely fall increasingly on smart grids towards achieving this. [Engerati- Greenhouse Gas Emissions May Boost Smart Grid Investments in the US]