California Can Reliably Hit 85% Clean Energy By 2030 Without Risking Outages – En Route To A 100% Clean Grid

Power crises during California’s August 2020 heat waves raised questions about how reliable the state’s grid will be on the road to its target of 100% clean energy by 2045.

But new research provides clear answers: California can reliably achieve an 85% clean electricity grid by 2030 with a diverse mix of renewables and batteries, flexible demand, trade with neighboring states, and some existing power plants—under multiple build-out assumptions and possible future conditions. It turns out a cleaner grid is a more reliable grid.

State regulators and elected officials can achieve this important step toward the state’s 100% clean energy future through policy actions that accelerate diverse clean energy deployment, reduce gas generation dependence, incentivize demand-side resources, and improve regional electricity trading coordination with neighboring states.

Policies to move forward

California is an international leader in reducing greenhouse gas pollution while providing increasingly clean power for a large and diverse population of electricity users – 40 million people and the world’s 5^th biggest economy. Energy efficiency measures have held total state power consumption flat for many years while a series of increasingly ambitious renewable portfolio standards have driven rapid adoption of clean energy supply from renewable resources like wind and solar.

State regulator ambitions have seen a fresh push. The California Public Utility Commission (CPUC) recently issued procurement orders for new clean resources and approved a new Preferred System Plan for its power providers aiming to reduce greenhouse gas emissions to 38 million metric tons (MMT) by 2030 and 35 MMTs by 2032, creating an 86% emissions-free power generation by 2032.

But even with these increased ambitions, California must do more to meet its goals for a reliable, zero-carbon future. A new technical report from Telos Energy and GridLab and accompanying policy report by Energy Innovation outlines how the state can meet this challenge.

A novel approach

The technical report provides a novel methodology to help policymakers rapidly evaluate many future resource portfolios and assumptions to secure a future clean energy grid. By including scenarios and sensitivities that examine reliability using details like hourly wind and solar data matched to hourly demand data for eight possible years across the Western U.S., modelers can compare benefits of different resource portfolios relatively quickly and at low cost.

Policymakers can then see how each portfolio makes the most efficient use of its 75% share of renewable resources across various years: Minimizing things like battery round-trip losses, the concentrated use of in-state gas resources and over-dependence on neighbors when regional demand is high.

The technical report also models key “stress conditions” that might threaten reliability, such as low-hydropower due to drought, import restrictions, gas plant retirements, coal plant retirements in neighboring states, and found each 85% clean electricity portfolio is reliable. In particular, the modelers simulated the hot weather conditions that caused rolling power outages in August 2020 and found an 85% clean electricity system would have ample electricity supply in a similar event.

Optimizing for an ambitious deployment schedule

This novel approach is particularly salient when considering the trailblazing acceleration in clean energy buildout needed for the state to achieve or exceed an 80% clean power annual goal for 2030. Modeling different portfolios allows policymakers to consider important tradeoffs—like the reliability role that battery storage, gas, and imports provide to a mostly solar- and wind-based system, and how that shifts when more consistent resources like geothermal and offshore wind are added to the portfolio.

Examining the reliability performance of various resource portfolios under key stressors empowers more efficient procurement after proposed portfolios have gone through all the regulatory hoops.

Case in point: The technical report’s “Resource Diversity” portfolio shown above reduces the need to build as many solar and onshore wind farms, cuts round-trip energy losses from cycling battery storage and relies less on fossil fuel power plants for reliability. It does this by including significant new offshore wind and geothermal generation resources, which produce power more consistently and complement other renewables, but with a higher price. Adding significant demand response to the mix offsets large battery storage needs. GridLab and Telos’ modeling highlights the non-cost reliability benefits of resource diversification and can be a valuable tool for all states working toward clean electricity targets.

As California energy agencies and its grid operator CAISO continue implementing the state’s clean energy policy agenda, they should incorporate the technical report’s novel approach to evaluate a broader set of portfolios while continuing the close collaboration on reliability and procurement they’ve exhibited since the August 2020 heat waves.

Specific efforts to plan for future offshore wind deployment and directly mandate the procurement of more diverse generation resources like clean firm renewables (typically geothermal) and long duration storage can be useful, but the reports point to how this could be done more organically and transparently. This type of analysis would complement the CPUC’s recent increased ambitions in resource planning and the new far-sighted CAISO 20-year transmission outlook.

A more equitable future from a cleaner grid

An equitable clean electricity transition depends upon investing in, and creating markets for economically viable clean energy portfolios that help retire natural gas units harming California’s most pollution-burdened communities. A just transition for impacted communities also includes increasing community resiliency, building clean resources with job and economic benefits, and using local consultation in selecting new investments.

The technical study’s multiple scenarios found that the state’s grid would be reliable even after retiring 11.5 gigawatts (GW), or about one third of California’s existing gas capacity. Though beyond the scope of the technical study, the companion policy report recommends prioritizing retiring gas plants located near or in disadvantaged communities no later than 2030, while zeroing out the state’s reliance on gas as soon as possible. Some agencies including the CPUC, have made some progress with inclusivity and environmental justice, but stalled efforts to retire gas show there’s more work yet to do.

State agencies and policymakers must focus on the root causes of natural gas’s continued use in California and develop a plan for phasing it out. This entails re-examining how new clean energy portfolios, and the use of demand-side resources could replace natural gas in providing reliability value at the system and local levels.

Planners should double down on resource diversity

Using insights from the technical study, the policy report shows how a more diverse set of clean resources can provide even more significant advantages to the state’s rapidly transforming grid. These advantages include reduced land-use and transmission needs, increased feasibility of reaching clean electricity targets, lower impacts on disadvantaged communities, and increased resiliency.

Resource diversity can come in many forms: supply resources (e.g., offshore wind, geothermal or distributed solar), resource location (different locations can provide complementary profiles), demand flexibility, and closer coordination with neighboring states. The technical study shows imported power from these neighbors often plays a key role in balancing the grid. Given the study’s finding that power reserves are available across the West when California needs it, closer coordination will allow California to rely on its neighbors more confidently.

California’s accelerated clean energy transition is an opportunity

Forging ahead with California’s clean energy transformation provides plenty of challenges to continue keeping the lights on, like how to keep building new infrastructure, engaging more deeply with electricity consumers to unlock distributed resources, and understanding the implications of depending on new resources like batteries that provide power in a pinch but need to be recharged.

However, this transformation also offers incredible opportunities through smarter planning and policy like fighting climate change, improving air quality in disadvantaged communities, adopting novel approaches for assessing the most effective combination of clean electricity resources, creating an arena for all kinds of technological innovation to flourish, and building a more resilient grid that will be a model for other states and countries.