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Tidal energy: “potential to provide a source of clean green energy to the UK”



Matthew Woodhatch of Groundsure writes in their blog: “Tidal energy has the potential to provide a reliable and predictable source of clean green energy to the UK.” Republished with the kind permission of Groundsure.

The world’s tides are controlled by a complex but predictable relationship between the position of the moon and the sun producing a gravitational pull on the Earth’s oceans, combined with the effect of the wind and ocean currents. Therefore, sites which are prone to large and powerful tidal variations can potentially generate vast amounts of energy.

In July 2011, the UK government released its Renewable Energy Roadmap report setting out the future plans of the UK’s renewable energy strategy. Within the report, the section on marine energy highlighted a future £20m worth of government funding which would be put into new innovation and commissioning of marine energy testing facilities and the National Renewable Energy Centre (Na REC).  With a potential of 300MW being deployed to the grid by 2020, securing investment for projects and infrastructure, along with consultation on strategic environmental assessments and policy making, was a priority outcome of the report.

Similar to wind turbines, tidal turbines consist mainly of a tower structure connected to the sea floor with a number of turbines attached underneath the water. Electricity is generated as tidal water passes through the turbine blades causing them to rotate.  The energy generated is then sent through a system of substations and underwater cables and fed into the national grid.

Tidal turbines have the potential to mitigate some of the argued negative aspects of offshore wind turbines.  A prominent objection to offshore wind farms is the visual impact on the Seascape highlighted recently which the objections raised to the Navitus Bay wind farm located off the Dorset coast. Local Conservative MPs and councils expressed concern that the project would “industrialise” precious views and have “catastrophic” consequences for thousands of tourism-related jobs. As a result, government ministers have recently vetoed the application for the Navitus Bay wind farm development.

Where have we come from?

One of the first tidal turbine installations in the UK is the SeaGen S project located at Strangford Lough, Northern Ireland, which was installed in 2008. The SeaGen S 1.2MW devices consist of a twin axial-flow turbine supported on a structure which has the ability to raise the turbines out of the water for maintenance. Since it was commissioned the SeaGen S turbine has generated over 8GWH of electricity. It has since been upgraded with 20m rotors, increasing its output to 2MW, generating power for 2,000 homes.

Where are we going?

Swansea Tidal Lagoon

In June 2015, a tidal lagoon project to be located in Swansea Bay was granted development consent by the Secretary of State.  The Tidal Bay Lagoon project (TLP) consists of a large 9.5km breakwater creating an 11.5 km2 lagoon, with a sluice gate housing 26 turbines. When the tide rises, the sluice gates open, allowing water to pass through the turbines and into the lagoon.  As the tide falls the sluices are closed while the sea level drops, then the sluice gates are opened and water passes back through the turbines into the sea. This gives the potential to generate electricity at four intervals during a 24 hour period. The lagoon would generate 320MW of electricity 14 hours a day for 120 years, producing enough electricity to power 155,000 homes, equivalent to 90% of Swansea Bay’s domestic energy use8.

The lagoon will also incorporate water sports and leisure facilities, an amenity not just for local people but capable of hosting international sporting events. A visitor centre, educational facilities, art work, marine-culture and conservation programmes have all been included in the lagoon’s design, creating a unique tourist attraction in its own right.  A Chinese construction company has been contracted to the build the project, and a core aim is to create a significant local economic benefit to Swansea Bay. The project hopes to start construction in late 2016 and could be operational by the end of the decade.

Kepler Energy Project

Another tidal energy project which utilises a new revolutionary turbine design is the Kepler energy project being proposed in the Bristol Channel. Instead of using a lagoon and turbine gate system, Kepler Energy propose to use a Transverse Horizontal Axis Water Turbine (THAWT), designed loosely on the principles of old water wheels. The turbines are connected together to form a long fence-type structure with the turbines placed in-between connecting towers.  The new THAWT design enables a significant quantity of power to be generated, even in shallow, low velocity tidal zones.

The project proposes to construct a 1km turbine fence at an estimated cost of £143m and to be potentially operational by 2020/2110. The 1km turbine fence has the potential to generate an estimated 30MW, enough to power 30,000 UK homes a year. To increase the power output of one site, additional fences can be easily added to the fence structure which can generate extra power once installed.

Bigger picture?

The UK needs to meet its renewable energy goal of 15% of total production by 2020 and with significant objections raised to onshore and offshore wind farms, tidal energy farms could be the answer to meet the 5% expected shortfall in renewable energy production.  Given that the vast majority of a tidal energy farm’s infrastructure is located underwater, the visual impact on the landscape in comparison to wind turbine farms would be significantly less. Tidal power could be one answer to securing future renewable energy production whilst also preserving the natural appearance of our shore and coast line.

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What Should We Make of The Clean Growth Strategy?



Clean Growth Strategy for green energy
Shutterstock Licensed Photo - By sdecoret |

It was hardly surprising the Clean Growth Strategy (CGS) was much anticipated by industry and environmentalists. After all, its publication was pushed back a couple of times. But with the document now in the public domain, and the Government having run a consultation on its content, what ultimately should we make of what’s perhaps one of the most important publications to come out of the Department for Business, Energy and the Industrial Strategy (BEIS) in the past 12 months?

The starting point, inevitably, is to decide what the document is and isn’t. It is, certainly, a lengthy and considered direction-setter – not just for the Government, but for business and industry, and indeed for consumers. While much of the content was favourably received in terms of highlighting ways to ensure clean growth, critics – not unjustifiably – suggested it was long on pages but short on detailed and finite policy commitments, accompanied by clear timeframes for action.

A Strategy, Instead of a Plan

But should we really be surprised? The answer, in all honesty, is probably not really. BEIS ministers had made no secret of the fact they would be publishing a ‘strategy’ as opposed to a ‘plan,’ and that gave every indication the CGS would set a direction of travel and be largely aspirational. The Government had consulted on its content, and will likely respond to the consultation during the course of 2018. And that’s when we might see more defined policy commitments and timeframes from action.

The second criticism one might level at the CGS is that indicated the use of ‘flexibilities’ to achieve targets set in the carbon budgets – essentially using past results to offset more recent failings to keep pace with emissions targets. Claire Perry has since appeared in front of the BEIS Select Committee and insisted she would be personally disappointed if the UK used flexibilities to fill the shortfall in meeting the fourth and fifth carbon budgets, but this is difficult ground for the Government. The Committee on Climate Change was critical of the proposed use of efficiencies, which would somewhat undermine ministers’ good intentions and commitment to clean growth – particularly set against November’s Budget, in which the Chancellor maintained the current carbon price floor (potentially giving a reprieve to coal) and introduced tax changes favourable to North Sea oil producers.

A 12 Month Green Energy Initiative with Real Teeth

But, there is much to appreciate and commend about the CGS. It fits into a 12-month narrative for BEIS ministers, in which they have clearly shown a commitment to clean growth, improving energy efficiency and cutting carbon emissions. Those 12 months have seen the launch of the Industrial Strategy – firstly in Green Paper form, which led to the launch of the Faraday Challenge, and then a White Paper in which clean growth was considered a ‘grand challenge’ for government. Throughout these publications – and indeed again with the CGS – the Government has shown itself to be an advocate of smart systems and demand response, including the development of battery technology.

Electrical Storage Development at Center of Broader Green Energy Push

While the Faraday Challenge is primarily focused on the development of batteries to support the proliferation of electric vehicles (which will support cuts to carbon emissions), it will also drive down technology costs, supporting the deployment of small and utility-scale storage that will fully harness the capability of renewables. Solar and wind made record contributions to UK electricity generation in 2017, and the development of storage capacity will help both reduce consumer costs and support decarbonisation.

The other thing the CGS showed us it that the Government is happy to be a disrupter in the energy market. The headline from the publication was the plans for legislation to empower Ofgem to cap the costs of Standard Variable Tariffs. This had been an aspiration of ministers for months, and there’s little doubt that driving down costs for consumers will be a trend within BEIS policy throughout 2018.

But the Government also seems happy to support disruption in the renewables market, as evidenced by the commitment (in the CGS) to more than half a billion pounds of investment in Pot 2 of Contracts for Difference (CfDs) – where the focus will be on emerging rather than established technologies.

This inevitably prompted ire from some within the industry, particularly proponents of solar, which is making an increasing contribution to the UK’s energy mix. But, again, we shouldn’t really be surprised. Since the subsidy cuts of 2015, ministers have given no indication or cause to think there will be public money afforded to solar development. Including solar within the CfD auction would have been a seismic shift in policy. And while ministers’ insistence in subsidy-free solar as the way forward has been shown to be based on a single project, we should expect that as costs continue to be driven down and solar makes record contributions to electricity generation, investment will follow – and there will ultimately be more subsidy-free solar farms, albeit perhaps not in 2018.

Meanwhile, by promoting emerging technologies like remote island wind, the Government appears to be favouring diversification and that it has a range of resources available to meet consumer demand. Perhaps more prescient than the decision to exclude established renewables from the CfD auction is the subsequent confirmation in the budget that Pot 2 of CfDs will be the last commitment of public money to renewable energy before 2025.

In short, we should view the CGS as a step in the right direction, albeit one the Government should be elaborating on in its consultation response. Its publication, coupled with the advancement this year of the Industrial Strategy indicates ministers are committed to the clean growth agenda. The question is now how the aspirations set out in the CGS – including the development of demand response capacity for the grid, and improving the energy efficiency of commercial and residential premises – will be realised.

It’s a step in the right direction. But, inevitably, there’s much more work to do.

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How Much Energy Does Bitcoin Use, Really?



how much energy bitcoin requires
Shutterstock Licensed Photo - By Chinnapong |

Many headlines have capitalized on the rapid rise of Bitcoin’s value. However, there’s a darker side of things that may entirely escape people’s awareness — the vast energy usage associated with Bitcoin mining. The practice involves adding information about transactions to a publicly accessible record called the blockchain.

Bitcoin miners increase the amounts of the cryptocurrency they own by being involved in mining. That means there is a built-in incentive to start mining and keep doing it. The energy consumption associated with mining may not be as visible as it is in traditional types of mining because everything happens in the digital realm — however, it’s exceptionally high, which is a cause of concern to many individuals in the know.

The Rise in Value Brings About Higher Energy Consumption

It’s not hard to find impressive headlines and news stories about how the value of Bitcoin has soared over the last few months. Many people even suspect they’ll soon witness the inevitable burst of a “Bitcoin bubble.” Miners are taking advantage of the current boom, though, which involves depending on power-sapping computers and related equipment.

In the early days of Bitcoin, it was possible to mine on basic home computer setups. Now, the most dedicated miners invest in the best computers around. In some cases, that means the machines they use are quite energy efficient, which is a good thing. However, the purchase of equipment that uses electricity well isn’t enough to make a significant dent in the overall Bitcoin energy usage.

The Approximate Energy Usage Statistics Vary

When you start doing in-depth research about just how much energy consumption Bitcoin demands, be prepared to come across many different figures. Although people are doing diligent research, they still can’t reach an agreement. For example, according to statistics from the Bitcoin Energy Consumption Index, the annual energy usage is just under 32 terawatt hours.

That’s the estimate for per-year energy use of Serbia and more than 150 other countries. However, analysts find it impossible to reach a unified conclusion about the per-transaction energy consumption for Bitcoins.

Figures from Digiconomist estimate one Bitcoin transaction takes 255 kilowatt-hours of power — or enough to power an American household for more than eight days. Marc Bevand, another analyst, disagrees with that figure, though his remarks on the matter are not as specific. He discusses how many of the highly publicized statistics fail to account for the technological innovations that occur as equipment improves.

He gives the example of an S9, which is a standard piece of Bitcoin equipment, claiming 16% of the S9’s revenues went towards electricity costs. If that figure is more accurate, it would mean each Bitcoin transaction uses enough power to keep an American residence going for just under four days.

Bitcoin Miners May Be Able to Branch Out From Cryptocurrency

Some Bitcoin miners are attracted to their trade for more reasons than just the lucrative and ballooning prices of the coins. People from a wide variety of industries, from banking to insurance, are looking at uses for blockchain technology. In the insurance sector, fraud costs $40 billion per year, but the verification method that miners understand and work with dramatically reduces fraud and makes blockchain appealing to insurance professionals.

Also, banks are increasingly researching Blockchain as a supplement to their current methods. As the prominence in the market goes up, the allure of being a Bitcoin miner does, too.

Also, going back to Bitcoin specifically, as the value of each coin goes up, people become more motivated than ever to invest in better technologies that help them remain profitable for as long as possible. When all these factors combine, it’s not hard to understand why energy consumption rises.

Do Banks Use More Energy Than Bitcoins?

Some analysts argue that even if the energy demanded by Bitcoins is exceptionally high, it’s still not at the level of energy used by banks. To keep things in perspective, it’s important to realize that the banking industry keeps its total energy usage figures under wraps, leaving people to do lots of speculating.

One analyst determined there are approximately 30,000 banks in the world, and each one has ATM networks, offices and other components that require electricity. When adding all the relevant factors together, the final figure this individual came up with is that banks use about 100 terawatts of power per year, less than the earlier-cited figure related to Bitcoins.

However, people have given opinions that the amount is too conservative. It does not include the energy used by bank employees, such as when employees drive to their offices or fly to meet clients. It bears mentioning, though, that the Bitcoin figures mentioned in this piece probably don’t either.

There are countless statistics about Bitcoin energy usage, and most of them are not promising. But instead of reading a few of them and immediately feeling shocked, it’s important for people to take a broad look at the findings and reach their own intelligent conclusions based on the collective research.

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