Russian scientists send organic PV into orbit

Russian scientists send organic PV into orbit

A team led by the Skolkovo Institute of Science and Technology (Skoltech) in Moscow has demonstrated an organic solar cell able to withstand 6,000 gray units (Gy) of gamma radiation, an achievement the institute says is a record high.

The performance raises hopes the cell could power satellites in near-earth orbit, where the researchers theorized the device could deliver operational lifetimes well beyond 10 years.

The cells are described in the paper Impressive Radiation Stability of Organic Solar Cells Based on Fullerene Derivatives and Carbazole-Containing Conjugated Polymers, published in ACS Applied Materials & Interfaces. The devices are based on a blend of carbazole-based polymers and a fullerene derivative.

Testing showed a composite film of those materials maintained more than 80% of its initial conversion efficiency after exposure to a maximum absorbed dose of 6,500 Gy. The researchers noted, NASA estimates satellites in geocentric Earth orbit are exposed to an average annual radiation dose of 160 Gy, making the organic compound tested by the Skoltech team a strong candidate to operate effectively in such an environment for more than a decade.

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The paper noted further advantages of using organic PV for satellite applications, including a high power to weight ratio, and flexibility. “Deploying space solar sails made of flexible plastic solar cells represents an enticing opportunity for ramping up the power of photoelectric converters on the satellites,” said Skoltech professor Pavel Troshin, who led the research group.

The same group recently evaluated a group of lead based perovskites for similar applications and found the cells quickly degraded under exposure to 5,000 Gy of radiation. A Chinese research group, meanwhile, discovered the lack of moisture in oxygen 35km from the Earth’s surface played to perovskite’s advantage.

Satellites requiring an energy source in space have mostly relied on III-V solar cells – so named because they incorporate elements from those groups of the periodic table. Alternative concepts such as organic PV and perovskites, however, potentially offer a much cheaper alternative.

SECI concludes world’s largest renewables-plus-storage tender at Rs4.04/kWh

For the renewable energy supplied during off-peak hours, SECI will pay pre-specified tariff of Rs 2.88/KWh (4.00 cents/KWh).

Thermal power has had its day in India, the head of a national PV trade body has claimed after the Solar Energy Corporation of India (SECI) concluded what it called the world’s largest renewables-plus-energy-storage capacity tender.

The procurement exercise was held to contract 1.2 GW of capacity in the form of assured supply of 600 MW of clean power for six hours daily during peak demand hours – 5.30-9.30am and 5.30pm-12.30am – on a day-ahead, on-demand basis. The successful bids comprised at least 3 GWh of energy storage capacity – pumped hydro or battery storage – plus associated clean energy generation assets.

The tender was staged to secure reliable, fixed-price energy supply for state electricity distribution companies otherwise hidebound to the vagaries of spot markets.

The procurement round was oversubscribed, with bids received for 1.62 GW of capacity and Hyderabad-based developer Greenko secured 900 MW of pumped-storage project capacity with the most competitive tariff bid for the clean energy to be supplied. Greenko offered a weighted average tariff of Rs4.04/kWh and a quoted peak tariff of Rs6.12/kWh.

Haryana-based ReNew Power secured the remaining 300 MW of capacity with a weighted average bid of Rs4.30 and quoted peak price of Rs6.85, marking a world record for renewables-plus-battery storage capacity.

For the renewable energy supplied during off-peak hours, SECI will pay a pre-specified tariff of Rs2.88/KWh. The tariffs granted will be paid over a 25-year period.

The Indian government has mandated all electricity distribution companies to source at least 21% of their energy from renewables by 2021-22 and has said grid operators will not incur transmission charges or losses on clean power.

“With this, thermal power in India has become priced out,” said Pranav R Mehta, chairman of the National Solar Energy Federation of India. “The most recent thermal power tenders in the country have yielded levelized tariffs in the range of Rs5-7/kWh ($0.0694-0.0972) at 85% annual PLF [plant load factor – a measurement of the output of a power plant compared to its maximum generation capacity]. The peak tariff under this SECI tender is highly competitive vis-à-vis the recent peak tariffs in international markets like [the] USA (Rs8-9/kWh or $0.1111-0.125).

“This is also lower than the recent stressed thermal projects tender conducted by [state-owned power trading company] PTC, where the tariff discovered was Rs4.24/kWh ($0.0589) for only [a] three-year supply [contract], whereas the tariff discovered under this tender is fixed for 25 years.

“With the peak time-of-day tariffs becoming more and more pronounced in India, these discovered tariffs will be value accretive for DISCOMs [electricity distribution companies], and are already much lower than the ever-increasing commercial and industrial consumer tariffs in India.”

Here are 5 reasons why the ocean is so important

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This article is brought to you thanks to the collaboration of The European Sting with the World Economic Forum. Author: Sean Fleming, Senior Writer, Formative Content Unless you’ve been making a superhuman effort to avoid the news recently, you’ll know that the ocean is vital to life on Earth. But why, exactly, is this the case?

Here are five reasons why we need to safeguard its future.

1. It helps us breathe

Phytoplankton – tiny plant-like organisms that live in the sea – are responsible for at least 50% of the oxygen on Earth.

Just like land-based plants, they contain chlorophyll to capture sunlight and use photosynthesis to convert it into the energy they need, producing oxygen as a byproduct. They also consume carbon dioxide, transferring about 10 gigatonnes of carbon from the atmosphere deep into the ocean each year.

2. It helps regulate the climate

The ocean absorbs huge amounts of heat from the sun. “More than 90% of the warming that has happened on Earth over the past 50 years has occurred in the ocean,” according to the US National Oceanic and Atmospheric Administration.

That heat tends to be at its most intense nearer the equator, with the water nearest the surface warming the most. Sea currents then transport that heat around the world; north and south, towards the poles. As some of the sea water evaporates it becomes denser and heavier, due to its relatively higher salt content. That causes it to sink, taking some of the warm water deeper.

From the surface to the depths, sea temperatures are rising. Image: NOAA

Some currents are directly responsible for specific climatic effects. One example is the Gulf Stream, which takes warmer water from the Gulf of Mexico across the Atlantic to Europe. If the Gulf Stream were disrupted, much of the western part of Europe – including the UK, Ireland and France – could become colder.

3. It’s an important source of food

Fish is on the menu for billions of people around the world every day. It accounts for almost 16% of all animal protein consumed globally. Of course, there’s more to seafood than fish, crustacea and other edible creatures. A range of algae and sea plants are also commonly used in cooking.

The UN Food and Agriculture Organization lists sodium, calcium, magnesium, and iodine among some of the important nutrients in seaweed. Iodine deficiency has been identified as the “most prevalent and easily preventable” cause of impaired cognitive development in children.

Pressure on resources and the environment have led to calls for food production and for people’s diets to change. A cow, for example, produces 2.8kg of greenhouse gas per kilo of live body weight and needs 10kg of feed for every kilo it weighs.

Plus, to get just one gram of protein from cattle, you need 112 litres of water. The oceans, if properly managed and maintained, could form an important part of a more sustainable approach to feeding the planet’s growing human population.

4. Its biodiversity is incredible

It’s not just a source of food. The ocean is also home to an abundance of life. While estimates on the number of species that live in the sea exist, no one knows with absolute certainty what that number is.

Back from the dead: The return of a living fossil. Image: BrokenSphere / Wikimedia Commons

One example of how mysterious the deep oceans can be is the coelacanth. Found in fossils and believed to be extinct, a living coelacanth was pulled out of the ocean in 1938 off the coast of South Africa.

This fascinating deep-water creature could yield invaluable insights into how marine animals were able to adapt to life on land, as the way they move their fins resembles the way many four-legged creatures walk.

What’s the World Economic Forum doing about the oceans? Our oceans cover 70% of the world’s surface and account for 80% of the planet’s biodiversity. We can’t have a healthy future without healthy oceans – but they’re more vulnerable than ever because of climate change and pollution. Tackling the grave threats to our oceans means working with leaders across sectors, from business to government to academia. The World Economic Forum, in collaboration with the World Resources Institute, convenes the Friends of Ocean Action, a coalition of leaders working together to protect the seas. From a programme with the Indonesian government to cut plastic waste entering the sea to a global plan to track illegal fishing, the Friends are pushing for new solutions. Climate change is an inextricable part of the threat to our oceans, with rising temperatures and acidification disrupting fragile ecosystems. The Forum runs a number of initiatives to support the shift to a low-carbon economy, including hosting the Alliance of CEO Climate Leaders, who have cut emissions in their companies by 9%. Is your organisation interested in working with the World Economic Forum? Find out more here.

5. It creates millions of jobs

By 2030, ocean-based industries will employ more than 40 million people worldwide, an OECD report estimates. The biggest share of those jobs is likely to be in the fisheries sector, followed by tourism.

The economic health of maritime industries is fundamentally linked to the overall health of the oceans, of course. The ocean economy is of particular importance in developing countries, which are home to most of the 3 billion people who rely on the sea for their livelihoods.

Challenges like climate change, pollution and a simple lack of awareness of sustainable ocean stewardship techniques continue to put maritime resources at risk. That will limit the potential socioeconomic benefits those resources represent for future generations, as well as stifling people’s earning abilities in the present.

It regulates rainfall and droughts, holds 97% of our planet’s water, and absorbs CO2, helping keep the carbon cycle in balance. From food to jobs, it’s a lifeline for billions of people, too.