July 25, 2019: The transition to a 100% renewable US power grid will need investment of up to $4.5 trillion over the next 10 to 20 years, require the installation of 900GW of energy storage as well as building 1,600GW of new wind and solar capacity, according to analysis from Wood Mackenzie released at the end of June.
Dan Shreve, head of global wind energy research at the international research consultancy, said: “The mass deployment of wind and solar generation will require substantial investments in utility-scale storage to ensure grid resilience is maintained.
“Energy storage is a vital component of the estimates, given the need to ensure wind and solar-generated power is available exactly when consumers need it.”
Shreve considered a total restructuring of the way the US sourced and used its power and created its energy storage would be needed.
“The challenges of achieving 100% renewable energy go far beyond the capital costs of new generating assets. Most notably, it will need a substantial redesign of electricity markets, migrating away from traditional energy-only constructs and more towards a capacity market.
“The current US power grid has about 1,060GW of nameplate capacity, including roughly about 130GW of wind and solar capacity.”
Aggressive 2030 climate targets would require more capacity to be installed every year for the next 11 than the total capacity put in place over the previous 20.
The move to renewables is starting to look unstoppable in the US. On July 18 a bill, dubbed the ‘most aggressive climate law in the US’, was signed off by New York governor Andrew Cuomo.
Known as the Climate Leadership and Community Protection Act, this requires utilities to source 70% of their electricity from renewable energy by 2030 and install 6GW of distributed solar by 2025. It aims to reduce greenhouse gas emissions by 85% by 2050.
Cuomo also signed off two offshore wind projects in what would be the country’s biggest renewable energy installation, 1.7GW, by any state in US history.
If the Wood Mac figures look unachievable in the near term, the consultancy says that extending the time horizon to 2040-2050 would allow new technologies to develop and reach commercial scale.
Allowing 20% of the power mix to come from existing natural gas-fired generation would also reduce renewable energy costs by roughly 20%, and energy storage costs by at least 60%, Wood Mackenzie found.
Issues such as the question of resources — material as well as monetary — look also to be part of a technological block to achieving these goals. Lithium batteries, which are now the standard in most large scale ESSs around the world, may not be the automatic way forward.
Jim Robb, president and CEO of the North American Electric Reliability Corporation, recently dubbed lithium ion batteries the “gatekeeper technology” for this expansion into the so-called clean energy transition.
Others, such as the International Lead Association, are arguing that lead batteries, with their proven record of reliability and cost-effectiveness, will also play a role in the future.
Oddly enough, reaching a halfway house in the clean energy transition may not be so impractical. Wood Mackenzie’s director of Americas Power Research Wade Schauer said: “Our analysis of the data suggest that reaching 50% of supply from intermittent renewables system wide is relatively straightforward in most of the US.
“But above 50%, integration challenges accelerate rapidly. Achieving full decarbonization will require long-duration energy storage, and the electric grid will need to roughly double its capability.”