In 2015, ASEAN established a goal of increasing renewable energy share in its energy portfolio from approximately 13–23% by 2025. Renewable electricity, especially intermittent and variable sources, presents challenges for grid operators due to the uncertain timing and quantity of electricity supply. Grid flexibility, the electric grid's ability to respond to changing demands and supply, now stands a key resource in responding to these uncertainties while maximizing the cost-effective role of clean energy. We develop and apply a grid flexibility assessment tool to assess ASEAN's current grid flexibility using six quantitative indicators: grid reliability, electricity market access; load profile ramp capacity; quality of forecasting tools; proportion of electricity generation from natural gas; and renewable energy diversity. We find that ASEAN nations cluster into three groups: better; moderately; and the least prepared nations. We develop an analytical ramp rate calculator to quantify expected load ramps for ASEAN in an integrated ASEAN Power Grid scenario. The lack of forecasting systems and limited electricity market access represent key weaknesses and areas where dramatic improvements can become cost-effective means to increase regional grid flexibility. As ASEAN pursues renewable energy targets, regional cooperation remains essential to address identified challenges. Member nations need to increase grid flexibility capacity to adequately prepare for higher penetrations of renewable electricity and lower overall system costs.
We found that scenarios relying on significant renewables were most cost effective, and that energy storage has a critical role to play.
We identified three imperatives that can help break down barriers and further the adoption of energy storage, plus recommendations for stakeholders.
The path to net zero
The transition to a low-carbon sustainable future is underway. In the United States, specifically in the Western region, more states and utilities are setting ambitious clean energy and electricity targets. The shape the transition will take has yet to be determined. Energy storage has been tapped as one critical enabler, given its ability to level the variability of electricity production, which in turn can increase grid reliability and stability.
In collaboration with the University of California, Berkeley’s Renewable & Appropriate Energy Laboratory’s (RAEL), we conducted a study to understand how the transition is unfolding in the Western U.S. region and, more specifically, the role of energy storage in providing flexibility to the grid. We used RAEL’s utility-sector operation and capacity expansion modeling capability (SWITCH), alongside our own research and energy storage experience, and assessed four scenarios to net zero in the Western Electricity Coordinating Council (WECC) region.
This piece by Annelise Gill-Wiehl and Daniel Kammen is featured in The Beam #11 – Power in People. Subscribe now to read more on the subject.
“Each time [the local workers] visit, we gain strength from that. To refill [LPG cylinders]. To continue on,” says Bibi Matunda (or Grandma Fruit as the old woman is kindly nicknamed) at a focus group with a few other families in the Community Technology Worker Pilot Program. In Tanzania, where our research is based, 96% of the population  relies on “unclean” fuels, and the effects of biomass burning and indoor air pollution contributes to 20,000 deaths . Liquified Petroleum Gas (LPG) is one of the truly clean cooking fuels based on emission criteria set by the World Health Organization (WHO). Although LPG is a fossil fuel, there is a net climate benefit to a large-scale switch to LPG for household fuel due to increased efficiency, as well as the benefit of transitioning away from the methane emissions caused by wood burning. Despite a wave of many African countries setting goals for increased or exclusive LPG use, LPG programs face common barriers to adoption of the clean fuel, which include a lack of education/need for household training, household safety concerns and the prohibitive cost.
We looked for analogies in other sustainable development fields that overcame barriers in behavior change and the need for community transitions. Specifically, we turned to the literature on Community Health Workers – local individuals who link their underserved communities to health systems.
Despite the existence of established and proven interventions to improve community health, local health systems are too fragmented to scale up these interventions. This weak infrastructure, combined with the shortage of over 4 million health care professionals and the high cost of training doctors, presented a need for a local worker to fill this health care void. A Community Health Worker (CHW) was implemented at the village level to provide individual care that was effective, culturally appropriate, and economical. The WHO defines CHWs as “members of the communities where they work, should be selected by the communities, should be answerable to the communities for their activities, should be supported by the health system, but not necessarily a part of the organization, and have shorter training than professional workers” . The public health community has overwhelmingly demonstrated that CHWs can increase community development and access to health services. We therefore decided to investigate whether a similar model – a Community Technology Worker (CTW) – could be introduced to aid in the adoption of clean stoves.
This work was piloted in Shirati, Tanzania, a town of ~50,000 on the edge of Lake Victoria, near the Kenyan border. Kubwana and Michire are two sub-villages in Shirati. Kubwana is a larger, electrified trading area with the regional hospital, small shops, and unofficial vendors selling vegetables, fruit, and charcoal. Michire is closer to the lake and has a smaller trading post without grid electrification – some shops have a single solar panel. A local NGO, ReachShirati, helped identify trusted community members, Mary from Michire and Nayome from Kubwana, to each start with 15 households. The local LPG company, Mihan Gas, was brought in to provide a day long safety training to supplement the manuals and explanations we provided on the LPG stove. The women then taught the families how to use the gas stove and provided educational and safety pamphlets in the native language that were supplemented with pictorial content for those who cannot read. They promised to always be available for questions or concerns. Mary and Nayome would check-in weekly with the households to conduct a short survey to gauge fuel use, but more importantly, they continue to provide support and encouragement to the families. After a year of surveys and rounds of interviews, the results show that roughly 80% of families report sustained, regular refilling of LPG cylinders. This is a relatively high rate of adoption compared to other LPG and improved biomass cookstove interventions.
A CTW does not remove all barriers to gas adoption. Economic difficulties and cooking materials stand in the way of full adoption. However, these results do suggest that a CTW does mitigate many of the obstacles through education and maintenance support.
To further bolster the effectiveness of the CTW model and encourage families to refill their LPG cylinder, we are continuing to conceptualize with other disciplines, specifically economics and microfinance. The research is attempting to expand and offer households an opportunity to opt into a savings bank option to promote accountability and a formal financial mechanism.
Our work is not the only clean cooking initiative to reach across disciplines and innovate to reach the world’s poor. There are many prominent ventures on the horizon in clean cooking, such as pay-as-you-cook SmartGas from Envirofit and Inyeryeri’s firewood pellet stove – one of the few biomass stoves to meet the Tier 4 Emission Criteria set by the WHO. These enterprises are combining disciplines with IT & computer science, mechanical engineering, and economics. This cross-disciplinary work is crucial to attack the most pressing environmental and global health issues. As we face a warming climate and growing health implications from the burning of biomass, it is all the more important for the sustainable development community to work together and lean on new ideas and identify proven bright spots, even those from different disciplines. We cannot look for solutions in silos; rather, we must reach out across disciplines and topics to achieve a sustainable future.
We must not forget to incorporate the most important aspect from both CHWs and CTWs – the human contact of local outreach. In theory, reach and scale are easily and quickly attainable even without physical visiting. However, even companies like Envirofit, who pursue large-scale cookstove deployment mostly through IT-based communication, admit that “while investing in training resources increases costs, it also increases adoption”.
The advantage of this model for cooking over an IT-based solution (i.e. text message education or reminders) is the flexibility and resilience inherent to a human-led initiative. Human workers can respond and adapt to the specific issues of the household and provide helpful advice; an automated text message is easily ignored and cannot adapt to specific circumstances. Households are more likely to adopt improved stoves if they have had prior exposure to a trusted individual or organization promoting the product. Additionally, these local trainers could be utilized to solve other community problems, such as water and sanitation technology or mini-grids. An interdisciplinary solution can be employed to solve a multitude of disciplinary problems.
The focus group reiterated the importance of community between the CTW and the households. For example, one woman said, “we have become friends, we greet each other, you find out what the problem is and you help. If there is a problem, we find a solution.” As the women of Shirati support each other within this program, so should the fields in sustainable development. Beyond an expanded study that couples this model with a savings bank as mentioned above, this work could become a strong private-public partnership. Mirroring the CHWs in Tanzania, LPG companies could coordinate their village LPG dealers with local governments to adopt this model, empower their communities from within, and work towards clean fuel adoption for decades to come. Community-based outreach and interdisciplinary solutions are invaluable in the effort to provide access and ensure adoption of clean energy for cooking and beyond.
 Clean Cooking Alliance, “Tanzania,” 2019. [Online]. Available: https://www.cleancookingalliance.org/country-profiles/41-tanzania.html. [Accessed: 30-Oct-2019].
 G. Health, “Community and Formal Health System Support for Enhanced Community Health Worker Performance A U.S. Government Evidence Summit FINAL REPORT Content,” 2012.
 Envirofit, “COOKING IN ONE MILLION KITCHENS: Lessons Learned in Scaling a Clean Cookstove Business,” 2015.
Physics and environmental research are more compatible than you might first think. Kate Ravilious talks to three leading physicists-turned-environmental researchers, to find out about their journey. For the original article, click here.
How many people study physics and then go on to forge a career in environmental sciences? Perhaps not a huge number, but those who have a “physics mindset” often bring a fresh perspective to environmental research. Today an increasing number of physicists are helping to tackle some of the world’s most pressing environmental challenges. For Daniel Kammen, a self-confessed Star Trek fan and director of the Renewable and Appropriate Energy Laboratory at the University of California, Berkeley, US, the migration from physics to environmental science was serendipitous.
“My path was very random, driven by a love of physics and way too many interests,” he says. Initially, Kammen’s dream was to be an astronaut. “I learned to fly planes, took acrobatic and sea-plane landing lessons, but I was ultimately screened out of the NASA astronaut qualification on the basis of vision,” he explains. However, Kammen’s infectious enthusiasm for understanding the world around him soon opened many other doors.
While studying physics at Cornell University, Kammen learned about astronomy and cosmology, worked in the low-temperature physics laboratories and in solid-state physics, where he published his first papers on solid-state masers, and eagerly absorbed courses on electrodynamics, quantum mechanics and quantum field theory. Then at graduate school, first at Stanford University and then at Harvard University, he was drawn towards cosmology, computational physics and neural networks.
How do we ditch fossil fuels?
But it was while doing a postdoc in neural computing at Caltech that Kammen realized he could apply his talents to environmental problems. “During my summers I volunteered on an energy project, introducing solar ovens to communities in Nicaragua (the US was blockading the country at the time), and as a result I published my first paper on energy in Nature,” he says.
Accessing all energy
That chance volunteer work set Kammen’s career on the path of both academic and activist. For the last 25 years his focus has been finding solutions to the energy needs of developing countries. Today his passion is “energy access” and he works largely with communities in East Africa, Central America – including the country that originally inspired him, Nicaragua – and on Native American lands in the US. “Physics has provided me with the most amazing training, and I consistently use it today in work on solar cells, network studies of energy grids, and in dynamical systems methods applied to all sorts of things,” he says.
- "Physics has provided me with the most amazing training"
Stepping sideways from physics into environmental sciences has required a flexible and open-minded approach, but Kammen relishes the challenge of learning new things. “I am keen to keep working in analytical methods and I always want to learn more in the humanities and social sciences, where I am just a baby,” says Kammen, who is editor-in-chief of the open-access journal Environmental Research Letters (produced by IOP Publishing, which also publishes Physics World).
Kammen’s unusual career trajectory led him to contribute to the Intergovernmental Panel on Climate Change (IPCC) in its early days; work which was rewarded in 2007 when the IPCC shared the Nobel Peace Prize. These days his goal is to “de-carbonize” society. Last year he joined a list of eminent scientists, business leaders, economists, analysts, influencers and representatives of non-governmental organizations to set up Mission 2020 – a collaborative campaign that aims “to bend the greenhouse-gas emissions curve downwards” by 2020. Over time Kammen’s research interests have taken many twists and turns, but his enthusiasm for Star Trek is one thing that hasn’t changed. “I still own Spock ears and generally win the game ‘identify the Star Trek episode with the shortest quote’,” he laughs.
Down to Earth
For Anny Cazenave – director for earth sciences at the International Space Science Institute in Bern, Switzerland and senior scientist at the Laboratoire d’Etudes en Géophysique et Océanographie Spatiales at the French space centre (CNES) in Toulouse, France – the journey to environmental science began with an interest in what lies beyond Earth. While doing her first degree in mathematics and physics, Cazenave, like Kammen, was fascinated by space, and had ambitions of becoming an astronomer. Gradually her interests evolved towards geophysics, and she did a PhD at the University of Toulouse on the rotation of the Earth. This led to a permanent position at CNES to develop satellite geodesy – the use of satellites to study the shape of the Earth, its gravity field and its rotation, solid Earth tides and so on.
When Cazenave accepted the position, she had no inkling of how her work might transform environmental research. “At that time [the 1970s] environmental science was not at the forefront of space activities,” she explains.
It wasn’t until the mid-1990s, when satellite technology was far more advanced, that scientists began to fully explore the use of satellites for environmental applications. In particular altimeter satellites – which send a microwave pulse down to Earth and measure altitude from the time it takes the pulse to return – started employing two different wavelengths, massively increasing the resolution at which they could map the Earth’s surface.
Scientists, including Cazenave, spotted the potential of high-resolution satellites for mapping the peaks and troughs of the sea surface, and realized that they represented a new way of monitoring sea level changes and ocean circulation. “Although I was not an oceanographer, I learned about it while working,” says Cazenave. “At the beginning of the 2000s, I also started to develop hydrology from space – the study of terrestrial waters using space techniques.”
- "Interdisciplinary research needs hard work but it is highly motivating too, and I’m passionate about learning new things"
Today Cazenave’s focus is using satellite data to monitor climate change, for example, sea level rise, land ice melt, ocean thermal expansion and changes in the global water cycle. She feels that her original background in maths and physics has been a useful tool, but flexibility and willingness to learn have also been key to enabling her to move into a new field. “Interdisciplinary research needs hard work, to gain experience in the field in which we are a newcomer, but it is highly motivating too, and I’m passionate about learning new things,” she says.
Unlike Kammen and Cazenave who came to environmental science via curiosity about space, Jennifer Burney of the University of California, San Diego, US, found her enthusiasm for the environment to be a consistent thread throughout her life. “I’ve always been an outdoorsy person, and growing up in New Mexico always had a strong interest in the natural world,” she explains.
How hurricanes replenish their vast supply of rainwater
Following a degree in history and science, Burney began a physics PhD at Stanford, developing a superconducting camera that captures images of cosmic bodies such as pulsars or exoplanets. Partway through her studies, Burney decided to defer for a year, so that she could volunteer with rebuilding efforts in Nicaragua after 1998’s Hurricane Mitch. “It was exciting to be in the field devising creative solutions,” she says.
After finishing her PhD, Burney’s desire to bring positive change to other people’s lives resurfaced and she followed a non-academic route, working for non-governmental organization the Solar Electric Light Fund on rural electrification around the world. “One project was solar-powered drip irrigation in West Africa,” she says. “They needed somebody to figure out how to evaluate the technology. That required assessing the design and how to make it cost-effective and sustainable.”
Over time Burney became intrigued by how energy and climate affect food security, water availability and agriculture, and in 2008 she transitioned back into academia via a postdoc at Stanford on food security and the environment. Her research has continued in this vein ever since. These days Burney investigates the couplings between human activity and the environment. However, her physics mindset is still at the forefront of everything she does.
- "I fundamentally see the world as a physicist, and ultimately most of my projects have that kind of ‘flavour’"
“I fundamentally see the world as a physicist, and ultimately most of my projects have that kind of ‘flavour’ – for example, in our projects trying to understand what role air pollutants play in impacting both climate and humans, I tend to think about how they change the radiative properties of the atmosphere and much less about the biological or chemical processes for example,” she says.
But Burney relishes the cross-disciplinary nature of her work. “You learn to see the world in a new way,” she says. And it is this willingness to see things from other people’s point of view, combined with a thirst for knowledge, that seems to have enabled Burney, Cazenave and Kammen to slide smoothly between physics and the environmental sciences. “Physics provides a fantastic toolkit, but environmental problems are the biggest challenge we have,” says Burney. “It will take all hands on deck.”
Enjoy the rest of the March 2018 issue of Physics World in our digital magazine or via the Physics World app for any iOS or Android smartphone or tablet. Membership of the Institute of Physics required
Kate Ravilious is a contributing editor to environment and energy at Physics World and its sister website environmentalresearchweb
April 27, 2017, PV News.
Kosovo must do more for renewables, European Union says
Citing a RAEL study, authored by Noah Kittner and Daniel Kammen along with colleagues from KOSID in Kosovo, the European Commission has said that Kosovo’s government needs to increase efforts to improve its energy system, and to provide more support for renewables, although it has recently revised its energy (and renewable energy) strategy up to 2020.
The European Commission (EC) has said that Kosovo should make more investments in the energy sector, and add further generation capacity from both thermal and renewable energy sources, in order to become able to plan the decommissioning of the country’s two coal power plants, which currently still cover almost all of its power demand.
In the report on Kosovo’s Economic Reform Programme for the period 2017-2019, published on the website of the Austrian Parliament, the EC said that the energy reforms recently implemented by the local government are not sufficient to improve the country’s troubled power market, which still relies heavily on coal and electricity imports.
Under its long-term energy strategy, which was approved last summer, Kosovo is expected to add 240 MW of power generation capacity from renewables, of which only 10 MW is for solar PV, while wind and biomass will account for 150 MW and 14 MW, respectively, with other renewable sources accounting for the remaining share.
Despite these plans, the local government is currently putting most of its efforts in the construction of the new coal power plant “Kosova e Re”, an investment that the EU itself considers necessary to replace the 40-year old Kosovo A Power Station (345 MW) near Pristina, and upgrade the 27-year old lignite-fired Kosovo B Power Station (540 MW) in Obilić. The future Kosovo Power Project (600 MW), which is being backed by the World Bank, includes the rehabilitation of the Kosovo B power plant, in order to bring it in compliance with EU standards.
According to the EC, Kosovo’s energy market suffers from the above-mentioned outdated production capacity, as well as low energy efficiency, a non-liberalized energy market and a tariff system that does not reflect real costs. The EC added that it is not clear if recent reforms of the energy market are aligned with the reforms included in the Energy Strategy. “Progress in 2016”, the EC stressed, “was mainly limited to legislative measures and the introduction of some energy efficiency measures.” The Commission also stressed that cost estimates of the new planned actions for 2016, which include the future coal power plant, three unspecified solar projects, 20 hydropower facilities and two wind power installations, “are very rough, and without a clear regulatory framework.” The EC also specified that all the work required by these actions was not done, except for the feasibility study for the rehabilitation of Kosovo B thermal power plant.
According to a report from Kosovo’s Ministry of Energy, solar had only a few hundred kW connected to the grid as of the end of 2015. The first solar PV projects with total installed capacity of 102.4 kilowatt were brought online in 2014. Under the FIT program run by the Ministry of Agriculture (MAFRD), 101 PV systems totaling 77 kW were installed in 2014, while further 135 installations with a combined capacity of 364 kW came online in 2015.
According to another report published in Environmental Research Letters by scientists of University of California, Berkeley on the scientific research journal IOPscience last year, at the end of 2015 the country had around 3 MW of solar installed under the FIT scheme, which was issued in 2014. The program is granting a 12-year FIT of €85 ($92.5)/MWh.
“A striking aspect of Kosovo is its substantial solar energy resource, yet complete lack of development of solar power,” said the report’s authors. “It receives about 80% of Arizona’s solar insolation. That’s a higher level of sunlight than Germany, which has extensive solar energy facilities.” Kosovo, indeed, has a considerable solar potential with an average of 278 sunny days and 2000 hours of sun per year.
The authors of IOPscience’s report also believe that distributed renewable and solar can better help Kosovo manage the necessary growth of installed generation capacity compared to large centralized projects. While PV systems can be installed incrementally on a per kW or MW scale, a coal plant requires full commitment to hundreds of MW capacity during one investment period, the report explains. “As demand for electricity changes,” the US researchers said, “the deployment of distributed renewables provides investors with increased flexibility to extend capacity in smaller sizes as to not leave the investor with large-scale stranded assets.”
With 2 million inhabitants, Kosovo is still a disputed land between Republic of Serbia, which claims it as it’s own territory after, and the Republic of Kosovo. Currently, 111 out of 193 member states of the United Nations have recognized Kosovo as an independent state.
We explore the operations, balancing requirements, and costs of the Western Electricity Coordinating Council power system under a stringent greenhouse gas emission reduction target. We include sensitivities for technology costs and availability, fuel prices and emissions, and demand profile. Meeting an emissions target of 85% below 1990 levels is feasible across a range of assumptions, but the cost of achieving the goal and the technology mix are uncertain. Deployment of solar photovoltaics is the main driver of storage deployment: the diurnal periodicity of solar energy availability results in opportunities for daily arbitrage that storage technologies with several hours of duration are well suited to provide. Wind output exhibits seasonal variations and requires storage with a large energy subcomponent to avoid curtailment. The combination of low-cost solar technology and advanced battery technology can provide substantial savings through 2050, greatly mitigating the cost of climate change mitigation. Policy goals for storage deployment should be based on the function storage will play on the grid and therefore incorporate both the power rating and duration of the storage system. These goals should be set as part of overall portfolio development, as system flexibility needs will vary with the grid mix.
BERKELEY, California — California is cruising toward its 2020 goal for increasing renewable energy and is setting far more ambitious targets for the future. Its large-scale solar arrays produced more energy in 2014 than those in all other states combined. Half the nation’s solar home rooftops are in the state, and thousands more are added each week.
With its progressive politics, high-tech bent and abundant sunshine, California is fast ramping up its production of clean electricity, setting an example its leaders hope the rest of the country, and other nations, will follow as they seek to cut emissions of climate-warming carbon dioxide.
“It’s hard to overstate the importance of California in terms of renewables,” said William Nelson, head of North American analysis at Bloomberg New Energy Finance. “It’s like an experiment in terms of how quickly we can add solar to the grid.
Fifteen years after an energy crisis, caused partly by deregulation and market manipulation, brought blackouts and price spikes, the shift has been remarkably smooth, many analysts say. Even without counting the big contribution from home solar generation, 26 percent of the state’s power this year will come from clean sources like the sun and wind, Bloomberg New Energy Finance estimates. The national average is about 10 percent.
Contracts already in place virtually guarantee that the state will reach its goal of getting 33 percent of electricity from renewables by 2020, a number that does not include most home generation. And at the rate California has been going, a new target of 50 percent for 2030 is within reach, Mr. Nelson said.
“It’s kind of a quiet revolution,” said Daniel Kammen, director of the Renewable and Appropriate Energy Laboratory at the University of California, Berkeley. “Nothing weird or strange has happened, electricity prices haven’t shot up or down.”
California has avoided the steep jump in prices that Germany initially suffered in its push for clean power. Renewables have added between 3 percent and 5 percent to the cost of energy, estimated the California Public Utilities Commission, a regulatory body. While per-unit prices are among the highest in the nation, stringent energy conservation measures have helped keep monthly bills $20 lower than the United States average, since Californian homes use almost 40 percent less electricity than the typical American household.
A new industry of home solar panel installation and financing, spearheaded by companies like SolarCity and Sunrun, has sprung up in California, and many of those companies have expanded elsewhere in the country, Mr. Nelson said.
“It’s a breeding ground of activity that is impacting other states,” he said.
California is not alone, of course, in its push toward renewables. Germany gets about 30 percent of its power from clean sources; Denmark has passed 40 percent and is aiming for 100 percent by 2050.
There have been difficulties. The big influx of solar and wind power has changed the hour-to-hour pattern of electricity production, with energy flooding the grid during the sunniest times, creating a mismatch with demand that has sometimes forced officials to temporarily switch off energy from the new sources.
The storage technologies that would help ease that imbalance are still too expensive to use widely, although California is requiring utilities to install 1.3 gigawatts of power storage by 2020.
New transmission lines are needed to keep up with the construction of solar and wind farms, and so are high-tech natural gas plants able to switch on and off quickly to complement the fluctuations of the sun and wind.
But so far the infusion of new clean energy has not caused reliability problems, as some critics had feared it might, said David Olsen, a governor on the board of the California Independent System Operator, which manages the state’s electric grid.
“We’ve seen no impact,” he said. “When we get to 40 percent, 50 percent, that will definitely be an issue. But we know what the technical issues are and we’re planning for them. We’re highly confident that we will be able to operate the grid reliably when it is dominated by renewable energy.”
The incentives and regulations driving the change are underpinned by an order in 2005 by then-Gov. Arnold Schwarzenegger that California slash greenhouse gas emissions by 80 percent from 1990 levels by 2050. In April, Gov. Jerry Brown added an interim target of a 40 percent emissions cut by 2030, also based on 1990 levels.
Last month, legislators wrote into law Mr. Brown’s goal of getting 50 percent of power from clean sources by 2030, although pressure from the oil industry forced the governor’s allies to drop a related piece of their climate package, a requirement to halve petroleum use.
Fong Wan, senior vice president for energy policy and procurement at Pacific Gas & Electric, said that while the utility supported the carbon-cutting goals, it wanted more freedom to decide how to reach them. Rather than mandating specific percentages of renewable power, he said, regulations should focus on the overriding goal of cutting emissions.
“We would like the flexibility to choose how to accomplish” those cuts, he said. “We are concerned with the unintended consequences or outcome if you have very specific goals, because you may end up with a suboptimal solution.”
Another utility priority has sparked a battle with the growing solar rooftop sector. Big providers like PG&E are losing revenue from customers who generate their own power, enjoying smaller monthly bills while still drawing on grid electricity at times. The utilities want those customers to pay a larger share of the cost of maintaining electricity lines and plants.
Regulators are considering revising rates to address that concern, angering rooftop panel companies who warn that a package of changes proposed by utilities would gut their industry and undermine California’s position as a climate leader.
Others predict the clean energy targets will harm the wider economy.
“Small businesses are worried about their own electric rates and large businesses are worried about whether they can produce and continue to grow in California,” said Loren Kaye, president of the California Foundation for Commerce and Education, a research group affiliated with the California Chamber of Commerce. “More and more industries that are even somewhat dependent on electricity are going to be lured elsewhere.”
The chamber, he said, would rather see a “cap and trade” approach that lets the market find the best way of cutting greenhouse gases. California has such an emissions trading system, but it currently has little impact on electricity, making a bigger difference in other areas, like the price of gasoline.
Officials say the renewables push has helped, not hurt, the economy.
“We have successfully delinked G.D.P. from carbon, and what that means is that we have had continued economic growth, we added 498,000 jobs, more jobs than any other state in the country in 2014, and at the same time we have greatly reduced carbon emissions,” Kevin de León, president pro tempore of the state senate, said in a phone interview. “That’s why the Chinese, the Mexicans, the European Union, the Indians are watching what happens” in California.
Chinese officials, working on their own enormous renewables program, have consulted with the state’s energy experts. California’s grid operator is helping Mexico set up its own independent grid-management body, Mr. Olsen said. And with every state required by President Obama’s Clean Power Plan to create a roadmap for cutting its carbon emissions, many are likely to look more closely at California’s efforts.
That impact, said Mr. Kammen of the University of California, Berkeley, will be critical if California’s work is to make a real difference in slowing the pace of climate change.
“The lessons from the Californias, the Denmarks, the Germanys have to really spread,” he said. “It doesn’t do us much good if a few places are really green, if the overall trajectory doesn’t change.”