Can California really be carbon-free by 2045?

Solar panels on the roof of the Los Angeles Convention Center. Image: Getty.

California governor Jerry Brown recently signed a new law mandating that the electricity the state consumes not cause carbon emissions by 2045.

He also issued an executive order that goes even further: it commits California to “achieve carbon neutrality” across the board and not just for power generation by 2045. Together, these steps codify California’s ongoing transition away from relying on fossil fuels for energy. This effort has been ramping up since 2011, when Brown signed another law committing the state to deriving a third of its energy from renewable sources like wind and solar power by 2020 – not including big hydroelectric dams.

Based on more than 30 years of research related to solar energy, by my assessment, California can meet the law’s ambitious goal as long as it continues to implement programs that encourage the rapid expansion of renewable energy in the state.

A growth industry

The new law actually sets multiple targets rather than just one. It commits California to draw half its electricity from renewable sources by 2026, a share that would rise to 60 per cent by 2030.

To take the next step, rather than mandating that all power be renewably sourced, state lawmakers established a 100 per cent “zero-carbon” goal. They did not define this term, but it is understood as including wind and solar power, big hydropower plants and other sources of electricity that do not generate carbon dioxide.

Utility-scale solar and wind electricity increased from 3 per cent in 2010 to 18 per cent in 2017 in California, exceeding prior state targets, largely because solar prices have dropped sharply in recent years.

Being open to a wide range of technologies makes meeting the 2045 target easier and allowed State Senator Kevin de Leon, the original bill’s author, to amass broad support for the bill.

Where things stood in 2017

About 56 per cent of the power California generated in 2017 came from sources that don’t emit carbon. That puts it more than halfway toward this new goal by 2045.

However, the Diablo Canyon plant, California’s last nuclear power station, is slated for decommissioning by 2025, and no other reactors are in the works. This closure would eliminate the 8.7 per cent of the state’s carbon-free power that came from nuclear energy.

Nearly all of the remaining 44 per cent of the state’s electricity is currently generated by burning natural gas, and virtually none comes from coal. Going completely zero-carbon would require phasing out the state’s natural gas power plants.

On top of wind and solar energy, other generation options include geothermal, small nuclear reactors and carbon dioxide sequestration.

One quirk about this legislation is that it deals only with utility-scale power. It would not preclude private electricity-generation facilities such as the diesel generator a farmer might use to pump water. Nor would it count the power generated by a homeowner’s rooftop solar panels.

When the sun shines

One complication is that the state’s mix of energy sources can vary a great deal, even from one hour to the next.

Consider what happened on 8 April 2018, for example. It was a generally sunny and windy Sunday, with relatively low electricity demand. At night, about 40 per cent of electricity was generated from renewable sources. But around noon that day, more than 80 per cent came from renewable sources including large-scale hydropower.

If the electricity generated from these renewable sources is approximately doubled, as I estimate is necessary to meet the 2045 target, the power available in the middle of the day would greatly exceed the demand for electricity at that time.

This challenge shifts throughout the year.

On 24 and 25 July, Californians were asked to voluntarily use less electricity between 5 p.m. and 9 p.m. to avoid an outage because of hot weather. Prices spiked by more than a factor of 10, helping to keep demand within the supply.

On those days, renewably sourced electricity never met half of the demand for power.

Balancing act

Due to this degree of variability, relying heavily on renewable energy will require ample energy storage and big investments in grid-based technology.

Today, the expected demand for electricity is balanced by the Independent System Operator, an entity that controls the flow of electricity on the grid and selects the lowest-priced sources of electricity available.

Pumped hydro storage, electricity generated from water pumped to a reservoir, is the state’s most common form of storage today. While limited to locations with large dams, the amount of energy stored this way could be increased in California, as recently proposed for Hoover Dam.

Big lithium ion batteries are becoming more affordable and are now beginning to be deployed on the utility scale. As battery and solar prices drop, it may become attractive to disconnect from the grid and use electricity generated by a solar system and stored by a battery.

Lower battery costs are also spurring the sales of more electric vehicles. Ideally, these vehicles could be charged at times when electricity is plentiful and cheap. By 2045, I believe they could be helping make the grid more stable.

Other options are becoming available. One example is utility-scale compressed air storage, where energy is stored as pressurised air.

And there is growing interest in solar thermal plants, which generate electricity from sunlight’s heat and use high-temperature storage to continue generating electricity after the sun sets.

The University of California Merced and many other wholesale electricity customers are saving money by using thermal storage. They chill water when rates are low and use the chilled water for air conditioning when electricity prices are high.


Wiggle room

Because California’s new law does not require that every watt be generated within California’s borders, utilities could keep buying electricity from nearby states, as long as they verify its origins are in keeping with the new law’s requirements.

And because the law does not define “zero-carbon,” it provides flexibility in how the state can meet this new target.

For example, California would allow the continued operation of natural gas plants when their output is coupled with purchase of renewable energy certificates, credits issued for the generation of renewable electricity that may be sold, from a utility that generates solar or wind power.

These credits arise through several kinds of arrangements. Perhaps the most common is through rooftop solar systems. Small-scale solar energy supplied about 5 per cent of California’s electricity in 2017. It is likely to grow because of California’s mandate for solar panels on most new homes, starting in 2020.

In assessing whether the goal of going zero-carbon by 2045 is realistic or not, it is worth considering that solar energy has grown for years at a pace that far exceeded projections: thanks to technological progress, government policies like California’s new law, market forces and the public’s demand for renewable energy.

The Conversation

Sarah Kurtz, Professor of Materials Science and Engineering, University of California, Merced.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

 
 
 
 

To make electric vehicles happen, the government must devolve energy policy to councils

The future. Image: Getty.

Last week, the Guardian revealed that at least a quarter of councils have halted the roll-out of electric vehicle (EV) charging infrastructure with no plans to resume its installation. This is a fully charged battery-worth of miles short of ideal, given the ambitious decarbonisation targets to which the UK is rightly working.

It’s even more startling given the current focus on inclusive growth, for the switch to EVs is an economic advancement, on an individual and societal level. Decarbonisation will free up resources and push growth, but the way in which we go about it will have impacts for generations after the task is complete.

If there is one lesson that has been not so much taught to us as screamed at us by recent history, it is that the market does not deliver inclusivity by itself. Left to its own devices, the market tends to leave people behind. And people left behind make all kinds of rational decisions, in polling stations and elsewhere that can seem wholly irrational to those charged with keeping pace – as illuminted in Jeremy Harding’s despatch from the ‘periphery’ which has incubated France’s ‘gilet jaunes’ in the London Review of Books.

But what in the name of Nikola Tesla has any of this to do with charging stations? The Localis argument is simple: local government must work strategically with energy network providers to ensure that EV charging stations are rolled out equally across areas, to ensure deprived areas do not face further disadvantage in the switch to EVs. To do so, Ofgem must first devolve certain regulations around energy supply and management to our combined authorities and city regions.


Although it might make sense now to invest in wealthier areas where EVs are already present, if there isn’t infrastructure in place ahead of demand elsewhere, then we risk a ‘tale of two cities’, where decarbonisation is two-speed and its benefits are two-tier.

The Department for Transport (DfT) announced on Monday that urban mobility will be an issue for overarching and intelligent strategy moving forward. The issue of fairness must be central to any such strategy, lest it just become a case of more nice things in nice places and a further widening of the social gap in our cities.

This is where the local state comes in. To achieve clean transport across a city, more is needed than just the installation of charging points.  Collaboration must be coordinated between many of a place’s moving parts.

The DfT announcement makes much of open data, which is undoubtedly crucial to realising the goal of a smart city. This awareness of digital infrastructure must also be matched by upgrades to physical infrastructure, if we are going to realise the full network effects of an integrated city, and as we argue in detail in our recent report, it is here that inclusivity can be stitched firmly into the fabric.

Councils know the ins and outs of deprivation within their boundaries and are uniquely placed to bring together stakeholders from across sectors to devise and implement inclusive transport strategy. In the switch to EVs and in the wider Future of Mobility, they must stay a major player in the game.

As transport minister and biographer of Edmund Burke, Jesse Norman has been keen to stress the founding Conservative philosopher’s belief in the duty of those living in the present to respect the traditions of the past and keep this legacy alive for their own successors.

If this is to be a Burkean moment in making the leap to the transformative transport systems of the future, Mr Norman should give due attention to local government’s role as “little platoons” in this process: as committed agents of change whose civic responsibility and knowledge of place can make this mobility revolution happen.

Joe Fyans is head of research at the think tank Localis.