Solar+Battery in One Device Sets New Efficiency Standard

on July 21, 2020
Ars-Technica

The drop in battery prices is enabling battery integration with renewable systems in two contexts. In one, the battery serves as a short-term power reservoir to smooth over short-term fluctuations in the output of renewable power. In the other, the battery holds the power for when renewable power production stops, as solar power does at night. This works great for off-grid use, but it adds some complications in the form of additional hardware to convert voltages and current.

But there’s actually an additional option, one that merges photovoltaic and battery hardware in a single, unified device that can have extensive storage capacity. The main drawback? The devices have either been unstable or have terrible efficiency. But an international team of researchers has put together a device that’s both stable and has efficiencies competitive with those of silicon panels.

Solar flow batteries
How do you integrate photovoltaic cells and batteries? At its simplest, you make one of the electrodes that pulls power out of the photovoltaic system into the electrode of a battery. Which sounds like a major “well, duh!” But integration is nowhere near that simple. Battery electrodes, after all, have to be compatible with the chemistry of the battery—for lithium-ion batteries, for example, the electrodes end up storing the ions themselves and so have to have a structure that allows that.

So, the researchers used a completely different sort of chemistry. Flow batteries use solutions of two chemicals that can undergo charge-exchange reactions, shifting them between two chemical states. The battery basically borrows those charges in order to produce current when discharging, or it pumps charges back in to shift the chemicals to their alternate state, thus charging the battery. Flow batteries have the advantage that their total storage capacity is simply dependent upon the total volume of solution you use.

While there are many chemistries capable of working in a flow battery, the researchers started with their photovoltaic system and used that to choose the battery’s chemistry.

Even here, they didn’t exactly use off-the-shelf hardware. There was silicon involved, but it was part of a two-layer solar cell. In this setup, one photovoltaic material absorbs a set of wavelengths that aren’t absorbed by a second; the first layer, by contrast, is transparent to those wavelengths absorbed by the second. This allows a single cell to absorb a much broader range of wavelengths than would be possible otherwise, upping its overall efficiency.

For their device, the bottom layer was silicon. On top of that is a layer of perovskite photovoltaic material. Perovskites are a potential next-generation solar material, useful because they’re made from cheap ingredients and can be created simply by evaporating a solution of the perovskite. Unfortunately, these chemicals also have a propensity to decay, which has made for short lifetimes in many experimental setups. The researchers here don’t try to solve all of these problems; they simply use a perovskite-on-silicon photovoltaic setup and don’t try to run it for long enough that chemical decay is an issue.

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Fractal Energy Storage ConsultantsSolar+Battery in One Device Sets New Efficiency Standard

Investment in Renewable Energy Transition Could Act as a Powerful Recovery MechanismFrom Covid-19, Says GlobalData

on July 17, 2020
Power-Technology

As the global economies try to mitigate the Covid-19 impact, investment in renewable energy expansion becomes a critical cog in the wheel towards the economic recuperation journey. Expanding the renewables will not only help countries deliver stronger climate action under the Paris Agreement but also fuel the economic activities across the value chain forming an effective recovery mechanism to recuperate from the Covid-19 crisis.

Amid the Covid-19 pandemic, renewable energy took the centre stage. With declining electricity demand, utilities focussed on generating electricity from cost-effective renewable sources. By the conclusion of 2030, the cumulative renewable installed capacity is estimated to be 3,600GW, approximately 1,900GW more than that of 2020, which is significantly lower than the required build-up of approximately 2,800-3,000GW for restricting the global temperature rise to 2°C.

Due to technological advancements, economies of scale and competitive auctions, the Levelised Cost Of Electricity (LCOE) for renewables has seen a steep decline. The LCOE of solar PV had witnessed a drop of 86% to reach 0.05USD/kWh in 2019 when compared with 2010. Likewise, for onshore wind, the drop was 50.0% to 0.05USD/kWh.

The declining LCOE has brought renewables at par with fossil fuel and in few countries even cheaper. This trend of cost competitiveness and innovation is likely to continue and could attract countries and investors to increase their appetite for renewables. For instance, 2019 saw the highest solar power capacity additions and also the highest investment in the offshore wind segment.

However, the planned investments in this sector until 2030 is lesser than the investments made in the last decade. The Covid-19 pandemic recuperation stimulus provides an excellent window of opportunity for governments to channelise their investments in the renewables to offset the silos in the future investment schedule. These were earlier incapable to reach the desired 2030 installations target, decarbonising the economy and putting forward a solid step towards climate sustainability.

Incorporating higher investments in renewable energy might provide an opportunity to increase the investments and make up for the shortfall in the required installed power capacity by 2030.

Hence, increased investments in renewable energy in the recovery packages would benefit greatly and usher in a multitude of economic benefits. Not only will it provide a better opportunity in addressing climate change goals and global warming issues but also creates new employment opportunities and stimulate economic activities.

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Fractal Energy Storage ConsultantsInvestment in Renewable Energy Transition Could Act as a Powerful Recovery MechanismFrom Covid-19, Says GlobalData

Solar Flow Battery Efficiently Stores Renewable Energy in Liquid Form

on July 15, 2020

Capturing energy from the Sun with solar panels is only half the story – that energy needs to be stored somewhere for later use. In the case of flow batteries, storage is relegated to vats of liquid. Now, an international team led by University of Wisconsin-Madison scientists has created a new version of these solar flow batteries that’s efficient and long-lasting.

To make the new device, the team combined several existing technologies. It’s a silicon/perovskite tandem solar cell, paired with a redox flow battery, which the team says will allow people to harvest and store renewable energy in one device. Not only is it efficient, but it should be inexpensive and simple enough to scale up for home use.

The energy-harvesting part of the equation combines the long-time industry-leading material – silicon – with a promising young upstart called perovskite. These tandem solar cells have proved better than either material alone, since the two materials capture different wavelengths of light.

For storage, the team turned to a flow battery. Traditionally, these devices contain two liquids, housed in separate tanks, that function as the electrolytes. Electricity from the solar cell charges one of the liquids, where it can sit more or less indefinitely. When the power is needed, the two liquids interact in a middle chamber, creating a chemical reaction that produces electricity.

The team used a theoretical modeling method to determine which chemicals would operate at the ideal voltage, to maximize efficiency. They settled on two organic compounds dissolved in saltwater, and tests with the final physical device confirmed that it was a good match.

The team recorded 20 percent efficiency, which is up there with the best. The device was able to maintain a high efficiency, and most of its capacity, over hundreds of hours and charge-discharge cycles. That gives it a much longer life than other flow batteries, whose acidic electrolytes tend to corrode the tanks.

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Fractal Energy Storage ConsultantsSolar Flow Battery Efficiently Stores Renewable Energy in Liquid Form

Sydney Switches to 100% Renewable Energy

on July 14, 2020

All operations in Sydney, Australia – including street lights, pools, sports fields, depots, buildings and the historic Sydney Town Hall – are now run on 100% renewable electricity from locally-sourced clean energy.

The switch is expected to save up to half a million dollars a year over the next 10 years. It will reduce carbon emissions by around 20,000 tonnes a year – or the power used by 6,000 average households. For more information see the IDTechEx report on Energy Harvesting Microwatt to Gigawatt: Opportunities 2020-2040.

Sydney sources renewable energy from 3 different generators – the Bomen Solar Farm in Wagga Wagga, Sapphire Wind Farm near Inverell and the Shoalhaven solar farm in Nowra.

The green energy switch was made using a power purchase agreement with Australian retailer, Flow Power. Valued at over $60 million, it’s the biggest agreement of its kind by a council in Australia. The new agreement will generate jobs, support communities impacted by the Covid-19 pandemic and create new opportunities in drought-affected regional NSW. Around three-quarters of the power will be wind-generated, and remaining will be solar.

The Shoalhaven project is being developed by Flow Power in partnership with local community group Repower Shoalhaven, a not for profit volunteer community enterprise that develops community solar projects. When finished, the 3-megawatt solar farm will have around 10,000 panels and generate enough energy to power 1,500 homes.

Speaking on behalf of Repower Shoalhaven, member Bob Hayward said the power purchase agreement will directly support the regional community. “Shoalhaven solar farm could not have become operational without the City of Sydney’s investment. By partnering with this project, we’re creating local jobs and helping the renewables sector grow,” Bob Hayward said. “The City of Sydney’s decision to include a regional community-based scheme brings us a step closer to a sustainable decarbonised future, while also supporting regional investment and employment. We congratulate the City of Sydney for this significant commitment.”

Owned by the Australian-listed company, Spark Infrastructure, the 120MW Bomen Solar Farm has more than 310,000 solar panels on 250 hectares of land. It’s one of the first projects in Australia to use bi-facial panels that absorb sunlight on both sides, with tracking technology that shifts each panel throughout the day to capture the sun’s energy.

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Fractal Energy Storage ConsultantsSydney Switches to 100% Renewable Energy

COVID-19 is a Game-Changer For Renewable Energy. Here’s Why

on July 14, 2020

COVID-19 has brought the generation of energy from fossil fuels to breaking point. As the lockdown measures were introduced, global energy demand dropped precipitously at levels not seen in 70 years. The IEA has estimated that overall energy demand contracted by 6% and energy-related emissions will decrease by 8% for 2020. Oil demand is expected to drop 9% and coal 8% for this year, while crude oil is at record-low prices.

Previous energy crises provide insight into what happens when the oil price crashes and how the use of fossil fuels has subsequently rebounded. But this crisis is different, because it is demand-led. The scale of the fall in demand, the speed of change, and how widespread it has been have generated a radical shift that seems to be more than a temporary short-term drop in demand for fossil fuels, at least in the power sector.

With the fall in demand, renewable sources (mainly wind and solar) saw their share in electricity substantially increase at record levels in many countries. In less than 10 weeks, the USA increased its renewable energy consumption by nearly 40% and India by 45% (see graph). Italy, Germany, and Spain set new records for variable renewable energy integration to the grid.

This rise in renewable energy is not circumstantial
Although the pandemic is circumstantial and unexpected, the current outcome for the power sector is not. The ongoing increase in renewable energy into the grid results from a mixture of past policies, regulations, incentives and innovations embedded in the power sectors of many forward-thinking countries.

These are three key factors behind the increase in renewable energy during this crisis:

  1. Renewables have been supported by favourable policies. In many countries, renewables receive priority through market regulation. The priority for the first batch of energy to the network is given to the less expensive source, favouring cheaper and cleaner sources.
  2. Continuous innovation. Renewable energy has become the cheapest source of energy. IRENA recently reported that the cost of solar had fallen by 82% over the last 10 years, while BNEF states that renewable energy is now the cheapest energy source in two-thirds of the world.
  3. Preferred investment. Renewable energy has become investors’ preferred choice for new power plants. For nearly two decades, renewable energy capacity has grown steadily, and now 72% of all new power capacity is a renewable plant.
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Fractal Energy Storage ConsultantsCOVID-19 is a Game-Changer For Renewable Energy. Here’s Why

The Next Energy Battle: Renewables vs Natural Gas

on July 13, 2020
The-New-York-Times

Dominion Energy, one of the nation’s largest utilities, in late June erected wind turbines off the Virginia coast — only the second such installation in the United States — as part of a big bet on renewable energy.

The company is also planning to build new power plants that burn natural gas.

Utilities around the country are promoting their growing use of renewable energy like hydroelectric dams, wind turbines and solar panels, which collectively provided more power than coal-fired power plants for the first time last year. But even as they add more green sources of power, the industry remains deeply dependent on natural gas, a fossil fuel that emits greenhouse gases and is likely to remain a cornerstone of the electric grid for years or even decades.

Utilities maintain that they need to keep using natural gas because the wind and the sun are too unreliable. They are also reluctant to invest in energy storage, arguing that it would cost too much to buy batteries that can power the grid when there isn’t enough sunlight or wind.

“We’ve got to have a resource that has an ‘on’ and ‘off’ switch,” said Katharine Bond, vice president for public policy and state affairs at Dominion.

For years, environmental activists and liberal policymakers fought to force utilities to reduce coal use to curb emissions and climate change. As the use of coal fades, the battle lines are rapidly shifting, with the proponents of a carbon-free grid facing off against those who champion natural gas, an abundant fuel that produces about half the greenhouse gas emissions that burning coal does.

Coal plants supply less than 20 percent of the country’s electricity, down from about half a decade ago. Over that same time, the share from natural gas has doubled to about 40 percent. Renewable energy has also more than doubled to about 20 percent, and nuclear plants have been relatively steady at around 20 percent.

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Fractal Energy Storage ConsultantsThe Next Energy Battle: Renewables vs Natural Gas

AEP is Putting Out The Call For Solar

on July 1, 2020

CHARLESTON, W.Va. — Appalachian Power is asking for bidders on up to 50 megawatts of solar energy resources in West Virginia.

The request was made possible by a bill passed by the West Virginia Legislature earlier this year.

The request for proprosal has a minimum bid size of 10 megawatts, an operational date of December 2022, and provides developers the option of including an energy storage system with their proposal.

To be eligible, the site must be in West Virginia and previously used in electric generation, industrial, manufacturing or mining operations to include brownfields, closed landfills, hazardous waste sites, former industrial sites and former mining sites.

Appalachian Power issued the request for proposals as part of the provisions of West Virginia Senate Bill 583, created to further the development of renewable energy resources and renewable energy facilities for solar energy.

“We’re pleased to support this legislation and make this opportunity available in our West Virginia service territory,” said Chris Beam, Appalachian Power president and chief operating officer.

“This RFP will help us identify viable large-scale solar projects to reduce customer costs and expand our renewables portfolio, while supporting efforts to repurpose sites that might otherwise be overlooked.”

Under the RFP, Appalachian Power may acquire a single or multiple solar facilities from winning bidders who meet certain economic and operational criteria. Qualifying projects must be operational by Dec. 15, 2022, and qualify for the Federal Investment Tax Credit.

To qualify for consideration, projects must be located in West Virginia and interconnected to Appalachian Power’s West Virginia distribution system or PJM. PJM is the independent regional transmission organization that manages the electric grid in 13 states, including West Virginia.

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Fractal Energy Storage ConsultantsAEP is Putting Out The Call For Solar

UN: Plugging Renewable Ambition Gap is ‘One of Smartest’ Ways Out of Pandemic

on June 15, 2020
PV-Tech

Countries have in low-cost solar and wind a chance to revive economies battered by COVID-19 but also rekindle the fight against climate change, according to the UN Environment Programme (UNEP), BloombergNEF (BNEF) and the Frankfurt School of Finance and Management.

The trio recently analysed commitments by state and private players and concluded that current pledges would deliver 826GW of new green energy by 2030, far below the 3,000GW the world would need by that year to avert catastrophic global heating.

According to the new review, the present 826GW pipeline – split (see table below) between government (721GW) and private sector targets (105GW) – would also fall short of the deployment that was achieved last decade, when 1.2GW of solar, wind and others was installed worldwide.

In a statement alongside the report, German Environment minister Svenja Schulze noted that 80% of power new-builds worldwide were renewable last year. Investors and markets, she said, no longer need convincing about the “reliability and competitiveness” of green energy.

According to the study, it is up to governments to act on the private appetite, and make renewables a core part of the COVID-19 recovery. Missing this chance now may make it even harder to find money later, as the pandemic tightens its hold of public and private budgets alike.

Should states move to ramp up renewable funding, they would find every dollar spent yields more, thanks to years of tumbling technology costs. As the study pointed out, the world only invested 1% more in green energy in 2019 but delivered 12% (or 20GW) higher installs year-on-year.

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Fractal Energy Storage ConsultantsUN: Plugging Renewable Ambition Gap is ‘One of Smartest’ Ways Out of Pandemic

The Pandemic Affects the Pace of Renewables’ Deployment, Not Its Future

on June 9, 2020

While the novel coronavirus pandemic stalled the expansion of the renewables sector in the U.S. and abroad, the industry is ready to ramp up as nations reopen.

“The largest effect from the pandemic we have seen [on the renewables’ industry] is the slowing of construction activity,” according to Erin Decker, director, cleantech client management for Schneider Electric. “It takes a long time for products to get built. There is slowing there, as well as slowing within the infrastructure and supply chain in the U.S. and Europe. There also is uncertainty in the capital markets, and some are slowing to look at new renewables in the U.S.”

Crises aside, renewables are poised for even more growth
Despite the economic slowdown of the past few months affecting construction, the U.S. Energy Information Administration (EIA) has forecasted that renewables will account for the largest portion of new electricity generating capacity this year. The EIA says it anticipates the power generation sector will more than 20 gigawatts of new wind power capacity and close to 13 gigawatts of utility-scale solar capacity in 2020 – in sum, the renewables sector will be the most rapidly growing source of power generation in 2020.

In a boost to the U.S. renewables industry, a recent IRS ruling allows solar and wind power companies with projects in the pipeline another year to get them online, due to the pandemic, and still receive the Federal Production Tax Credit. “Every business has had to adjust for safety, as the world emerges, and that goes for renewable energy as well,” added Decker.

Not to mention that goals for clean energy remain in place and banks and investors view renewable energy as a solid investment, according to Renewable Energy World.

Wind and solar power continue to be the dominant renewable energy in the U.S., and more companies are eager to finance projects through renewable energy certificates and power purchase agreements. “Some have invested directly,” Decker said. “There have been massive amounts invested by corporations already.”

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Fractal Energy Storage ConsultantsThe Pandemic Affects the Pace of Renewables’ Deployment, Not Its Future

Hawaii Leads Way in Long Duration Battery Storage on Road to 100% Renewables

on June 5, 2020
Renew-Economy

The island state of Hawaii has clearly taken the lead in the global pursuit of long duration battery storage, after its main electric utility revealed this week the details of 16 winning battery storage tenders in a second round of auctions that feature up to eight hours of battery storage.

The results are quite stunning for an industry used to being told that batteries are not a reasonable proposition for more than two or four hours of storage, and are normally best in shorter periods where their fast, accurate and flexible response make them ideal to provide essential grid services such as frequency control and more recently inertia.

However, storage lengths of two to four hours have become more common as the owners of large scale wind and solar farms look to store more output to ensure they can be put into the grid when needed most, and when prices are higher. Four hour battery storage proposals have become common in states like California, where batteries are increasingly preferred to peaking gas generators.

Now, Hawaii has pushed the barriers even further back. All but two of the battery storage proposals announced for the islands of Oahu, Maui and Hawaii feature at least four hours storage, while one 30MW project put forward by leading US developer AES proposes eight hours storage (240MWh) on the island of Oahu.

The deep storage proposed for Hawaii is likely a matter of need: It has fewer options for pumped hydro or other non-fossil dispatchable generation, and not so many possibilities for wind energy, which might have offered some balance to the solar plans.

The proposals were detailed by Hawaiian Electric, which is at the forefront of the local government’s law to reach 100 per cent renewables by 2045 – largely to replace the huge bill for imported oil and gas, and the last remaining coal fired generator on the island of Oahu which is due to close in 2022.

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Fractal Energy Storage ConsultantsHawaii Leads Way in Long Duration Battery Storage on Road to 100% Renewables