Green Energy

New Delhi: Renewable energy developer Leap Green Energy announced it will raise $250 million as primary capital to fund its expansion plans. The company currently has operational wind energy capacity of 750 Megawatt (Mw) and 400 Mw of under-construction wind assets.

Leap Green Energy is targeting to have an installed capacity of above 3,000 MW by 2019-20. To meet the fund requirements of expansion, the company plans to raise close to $250 million as primary capital,” the company said in a statement.

The company has appointed Barclays Bank PLC as financial advisors for raising equity which will help pursue greenfield and brownfield opportunities for growth within the renewable energy space. Apart from opportunities in power generation, the firm also intends to look at opportunities in energy storage, repowering and offshore wind energy.

“With less than USD 120 million invested, the company has created an operating capacity of over 750 MW. We are keen to further enhance this growth to reach our target of over 3 MW power generation in the next two years. For this we found Barclays PLC to be our apt financial expert partners to raise our next round of equity,” Founder and Managing Director Rajeev Karthikeyan said.

The company said it had reported total revenue of Rs 525 crore last financial year ended March 2018. Currently, Leap Green operates assets in Madhya Pradesh, Rajasthan, Tamil Nadu, Maharashtra and Gujarat and plans to enter more states.

Scottish Power, one of Britain’s biggest energy companies, has said it will invest in solar power for the first time as part of its move away from fossil fuels.

The big six firm sold off its last gas-fired power stations to Drax Group this week to focus exclusively on renewables, which today consists of onshore and offshore windfarms.

But Keith Anderson, the company’s chief executive, told the Guardian he had decided to move into solar, too.

“The solar market has had difficulties over the last wee while. But you look at where the technology cost is getting to, and the possibilities of integrating it with wind … how it balances from season to season wind and solar output, and we see a good opportunity there for further investment.”

Solar farms around the UK have historically been built by smaller energy firms and community groups, so the entrance of such a big player would mark a major shake-up. It could also inject life into a sector that has stalled in the face of subsidy cuts.

Researchers have argued that the comparatively low wind output across Europe this summer because of hot, still weather was a reminder of why energy companies should be investing in solar as well as wind.

Anderson said that Scottish Power had moved to 100% renewables because it was cheaper than other sources.

“We need to invest in the cheapest forms of energy – that’s onshore wind, offshore wind, it’s going to be solar – and that will help drive down the cost of energy,” he said.

The world’s need to tackle climate change also made it clear that companies needed to embrace green energy wholeheartedly, he said.

“Look at the IPCC report last week. My absolute belief is that organisations need to be at the forefront of that change. We can’t be part of the problem, we have to be part of the solution.”

Scottish Power would be competing in an auction next summer for a slice of £557m in government subsidies for offshore windfarms, Anderson confirmed.

The firm hopes to secure a contract for its planned 1,200MW East Anglia Three project, which would be capable of powering nearly 900,000 homes and dwarf the world’s current biggest, a 659MW scheme off the Cumbrian coast.

Anderson also expressed confidence that ministers were nearing a rethink on their block on subsidies for onshore windfarms, which the Conservatives barred when they came to power in 2015. “We’re closer than we’ve ever been before,” he said.

A poll this week found that two thirds of people living in rural Scottish communities, which are considered to have some of the best sites for prospective sites, support onshore windfarms.

But the prospect for new gas power stations – which companies including Drax and Germany’s RWE want to build – were bleak, Anderson said.

“Right now the commercial signals don’t exist to build a new gas plant in the UK. That might change in the future, but it’s not something we’ll get involved in.”

Washington State energy provider Puget Sound Energy announced this week that the second round of its Green Direct program has been fully subscribed, providing participating local councils and businesses with an opportunity to purchase 100% of their energy from local renewable energy sources.

Puget Sound Energy (PSE) announced on Tuesday that the second round offering of its Green Direct project had been fully subscribed, with participants benefiting from a mixture of wind and solar, including a 120 megawatt (MW) solar farm, Washington State’s largest such project. In addition, Green Direct is supported by the 137 MW Skookumchuck Wind Project which will be built in Lewis County, Washington. Further details about the project developers is not available, as of yet.

The Green Direct initiative was approved by the Washington Utilities and Transportation Commission (UTC) in early 2017 and presaged the first round which provided cities, government institutions, and major commercial customers with the opportunity to source their electricity from renewable energy sources. Companies sign long-term Power Purchase Agreements through the initiative to source renewable energy to meet all or part of their operations. Amidst the numerous cities and government institutions, big-name commercial clients including Starbucks and Target also signed up to the first round offering.

Green Direct led to Puget Sound Energy’s commitment to reduce its carbon footprint by 50% by 2040, which it announced in December of 2017. Specifically, the company committed to transitioning away from coal by the early 2030s after closing down several of its coal operations during the 2020s. PSE has also committed to securing renewable energy projects, building on the popularity of its Green Direct project.

Fast-forward over a year and Puget Sound Energy has announced that its second round offering has been completely subscribed, following approval from the Washington UTC. In addition to more local cities and government institutions — including the Washington Departments of Ecology, Health, Labor & Industries, and Social & Health Services — two big-name companies to join on to Green Direct include telecommunications giant T-Mobile retail megalith Walmart.

Walmart will secure enough renewable energy through Green Direct to power 12 stores — approximately 72% of the company’s load under Puget Sound Energy.

“Walmart is happy to join PSE and others in supporting the Green Direct program and the new renewable energy resources being supplied via the program,” said Steve Chriss, Director of Energy and Strategy Analysis for Walmart, Inc. “This initiative will play an instrumental role in Walmart’s efforts to increase our renewable energy use and enhance our ongoing sustainability efforts.”

T-Mobile, on the other hand, will receive enough clean energy to power its Bellevue headquarters with 100% renewable energy by 2021 — when the initiative’s latest solar project is set to come online.

“At T-Mobile, we really mean it when we say we’re going to clean up wireless for good … and in this case that means cleaning up our impact on the planet by making a BIG commitment to renewable energy,” said John Legere, CEO of T-Mobile. “We’ve put a stake in the ground to go 100% renewable by 2021 — because it’s the right thing to do and it’s smart business.”

With the price of photovoltaics having plunged dramatically, solar is likely to become a major contributor to the electrical generating mix in many countries. But the intermittent nature of photovoltaics could put a limit on how much they contribute to future grids or force us to develop massive storage capabilities.

But photovoltaics aren’t the only solar technology out there. Concentrated solar power uses mirrors to focus the Sun’s light, providing heat that can be used to drive turbines. Advances in heat storage mean that the technology can now generate power around the clock, essentially integrating storage into the process of producing energy. Unfortunately, the price of concentrated solar hasn’t budged much, and photovoltaics have left it in the dust. But some materials scientists may have figured out a way to boost concentrated solar’s efficiency considerably, clawing back some of photovoltaics’ advantage.

Feel the heat

Solar thermal revolves around transfers of heat. Sunlight is used to heat up a working fluid at the mirrors’ focus. That then transfers the heat either to a storage system or directly to another fluid that is used to drive a turbine—typically steam. Higher temperatures typically mean more work can be extracted, making the efficiency of these transfers critical.

Above a certain temperature, it becomes possible to replace the steam with supercritical carbon dioxide. This works more efficiently, potentially providing a boost of more than 20 percent, but it requires temperatures in excess of 1,000K. That makes things a bit more challenging, given that many metals will melt at such temperatures; others will react with carbon dioxide under these conditions. Finding a material that could work involves balancing a lot of factors, including heat and chemical resistance, ease of manufacture, and high heat transfer rates.

The researchers involved in the new work, a large US-based collaboration, focus on a composite material: tungsten and zirconium carbide. These have extremely high melting points: 3,700K for both materials. Both of them conduct heat extremely well, and neither of them expands or softens much under these conditions, meaning they would hold up better to the mechanical stresses.

While the stats are impressive, the amazing part of this is how the material is fabricated. The researchers started with tungsten carbide, a ceramic that can be formed into a porous material simply by pouring it as a powder into a mold and heating it. At this point, the ceramic can be further machined to produce a final shape. Once in its final form, the ceramic was placed in a bath of a molten mixture of copper and zirconium. The molten mixture filled the pores, and the zirconium reacted with the tungsten carbide, replacing the tungsten. The copper in the molten material formed a thin film on the surface of the solid.

The tungsten then filled the pores in the resulting material, allowing it to retain the same shape and size despite the chemical changes. The zircon carbide ends up providing the material with a stiffness even at high temperatures, while the tungsten is flexible enough to keep the whole thing from being brittle. And the whole thing conducted heat better than the metals currently in use.

The remaining issue is that, at the conditions involved in solar thermal plants, the copper on the material would react with the carbon dioxide, forming a copper oxide and releasing carbon monoxide. But the researchers determined that adding a small amount of carbon monoxide to the supercritical CO2 would suppress this reaction, something that they confirmed experimentally.

The economics

Because the material holds up to these conditions so much better than the metals currently in use, it’s possible to use much less of it to build a heat exchanger. This is great economically (since you need fewer raw materials), and the small size increases the power density and efficiency of the heat exchanger.

While a big boost in efficiency is great, concentrated solar is far enough behind photovoltaics on price that it’s not going to make a big enough difference in a direct competition. But the real competition here isn’t directly with photovoltaics; instead there are two separate competitions. One is against photovoltaics plus batteries, since only that provides the possibility of around-the-clock energy access. Here, the costs are changing fast enough that it’s difficult to figure out where things stand.

The other competition would be with traditional fossil fuel plants, where concentrated solar can provide a direct replacement in a way that photovoltaics can’t. But the situation here is murky as well. As some countries start to get serious about their commitments to lowering emissions, there’s a possibility that they’ll find ways of pricing emissions-free energy production in a way that helps improve concentrated solar’s competitiveness. One problem here is that both natural gas and nuclear plants also rely on heat exchangers, and there’s no reason this material can’t be used to boost their efficiency, too.

Centrica Business Solutions released a “Buyers Guide to Solar” to help large energy users better understand the ways they can improve their organization’s energy efficiency and operational performance.

The 18-page guide provides an end-to-end overview of solar and the option to combine solar and storage as an integrated solution. The report also describes the economics of going solar, various financing options, types of solar installations, and technology and system monitoring to verify productivity.

We’re now seeing the costs coming down, and more run hours where we can finance projects similar to Solar PPAs,” said Stephen Prince, Head of Centrica Business Solutions North America. “We can transact and include storage and the economic value in a number of different contract structures. Even a year ago it was limited.”

Solar in Use

Centrica Business Solutions installed a solar system at Reed Intermediate School in Newtown, Connecticut, which reduced energy costs by 43% with an estimated savings of $1.5M over 25 years. Financed through a Power Purchase Agreement with the Connecticut Green Bank, the building owners could go solar with no upfront costs, delivering immediate savings on electricity. In some states, there are robust incentives that have made solar more affordable for organizations considering renewable energy sources.

Incentives, coupled with declining costs, are driving more organizations toward renewable energy.

“The cost of solar and energy storage continues to decline at a rate that exceeds predictions even with tariffs,” said Prince.“We’re seeing rapid maturation of energy storage. The financing community is getting more comfortable how to underwrite big projects, instead of one-offs or backed shared savings agreements.”

In September, Centrica announced the purchase of Vista Solar, a leading California solar engineering, procurement and construction (EPC) company serving commercial, institutional and industrial customers. Serving customers from coast to coast, Centrica Business Solutions has a dedicated team of solar experts to help maximize savings and efficiencies.

The Future of Energy Use

In August, Centrica published a study that found most businesses will take control of their own energy use by generating a quarter of their electricity onsite by 2025, with 81% of US businesses predicting this change will take place in just seven years.

The study of more than 1,000 global businesses was launched to identify the key drivers and barriers to adopting new energy approaches including battery storage, on-site generation and demand side response.

Around one-quarter of businesses have already invested in on-site generation in the form of solar and/or combined heat and power (CHP) with one-third considering investing in these technologies. The increase in demand for flexibility that rewards businesses for increasing, decreasing or shifting their energy use has been identified as an opportunity by 44% of businesses planning to feed energy into the grid in the future, according to the report.

New research could someday put solar heat-to-electricity generation in direct cost-competition with fossil fuels.

Researchers from Purdue University and the Georgia Institute of Technology have created a new material, that when paired with a new manufacturing process, could more efficiently generate electricity from the sun’s heat.

“Storing solar energy as heat can already be cheaper than storing energy via batteries, so the next step is reducing the cost of generating electricity from the sun’s heat with the added benefit of zero greenhouse gas emissions,” Kenneth Sandhage, Purdue’s Reilly Professor of Materials Engineering, said in a statement.

Along with the solar panels commonly used on farms and rooftops, concentrated power plants that run on heat energy generate electricity by using mirrors or lenses to contribute a substantial amount of light onto a small area. This generates heat that is then transferred to a molten salt.

Heat from the molten salt is then transferred to a working fluid—supercritical carbon dioxide—that expands and works to spin a turbine to generate electricity.

However, to make this process cheaper, the turbine engine would need to run hotter to generate more electricity using the same amount of heat.

This is difficult to do because heat exchangers, which transfer heat from the hot molten salt to the working fluid, are currently made of stainless steel or nickel-based alloys that get too soft at the desired higher temperatures and elevated pressure of supercritical carbon dioxide.

To overcome these hurdles, the researchers combined a ceramic zirconium carbide and tungsten metal to create plates that host customizable channels tailored to the exchange of heat.

After conducting mechanical and corrosion tests, the team found that the new composite material could ultimately be tailored to successfully withstand both the higher temperature and the high-pressure supercritical carbon dioxide required to more efficiently generate electricity that the heat exchangers currently being used.

The researchers also performed an economic analysis on the new process and found that the scaled-up manufacturing of the new heat exchanges could be conducted at a comparable or even lower cost than the stainless steel or nickel alloy-based heat exchanges.

“Ultimately, with continued development, this technology would allow for large-scale penetration of renewable solar energy into the electricity grid,” Sandhage said. “This would mean dramatic reductions in man-made carbon dioxide emissions from electricity production.”

Solar power currently accounts for less than 2 percent of electricity in the U.S., while fossil fuels generate more than 60 percent. The researchers believe solar power could one day generate more than half the electricity in the country if the costs are reduced.