Renewable Energy

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Special Report on Renewable Energy Sources and Climate Change Mitigation IPCC Working Group III; 2012

The IPCC Special Report on Renewable Energy Sources and Climate Change Mitigation (SRREN) provides a comprehensive review concerning these sources and technologies, the relevant costs and benefits, and their potential role in a portfolio of mitigation options.
For the first time, an inclusive account of costs and greenhouse gas emissions across various technologies and scenarios confirms the key role of renewable sources, irrespective of any tangible climate change mitigation agreement.


Renewable Energy BBC Radio 4 - The Bottom Line

Wind Energy *

Solar Power *

Intermittency, capacity factor, grid integration

Renewables and grid reliability Challenges integrating renewables

ANALYSING TECHNICAL CONSTRAINTS ON RENEWABLE GENERATION TO 2050 A report to the Committee on Climate Change; Mar 2011

Huge Boost For Renewables' Output And Reliability Just From Location Planning Jeff McMahon; Forbes; 22 Apr 2016

California could boost its solar and wind energy output by nearly 50 percent and reduce volatility just by planning where new plants are installed, according to a Stanford economist. Solar and wind developers tend to cluster installations in locations that offer the highest revenues, said Frank Wolak, director of Stanford University’s Program on Energy and Sustainable Development. But these same locations accentuate volatility, raising the peaks when all are producing and deepening the troughs when all shut down.

Europe has adopted clean energy with so much gusto they've created a strange new problem Rebecca Harrington; Business Insider; 30 Mar 2016

Europe gets so much of its energy from renewables that many leading countries are now facing a new problem: updating their energy grids to handle it all.

Managing Flexibility Whilst Decarbonising the GB Electricity System - Executive Summary and Recommendations Energy Research Partnership; Aug 2015

The Energy Research Partnership has undertaken some modelling and analysis of the GB electricity system in the light of the carbon targets set by the Committee on Climate Change. Firstly a brief examination was made of the German and Irish markets with the hope of learning from their advanced penetration of variable renewables. Secondly a new model, BERIC, was written to simultaneously balance the need for energy, reserve, inertia and firm capacity on the system and its findings compared with simpler stacking against the load duration curve. The intention was to assess the need for flexibility on the system but some broader conclusions also emerged: A zero- or very low- carbon system with weather dependent renewables needs companion low carbon technologies to provide firm capacity
The modelling indicates that the 2030 decarbonisation targets of 50 or even 100 g/kWh cannot be hit by relying solely on weather dependent technologies like wind and PV alone. Simple merit order calculations have backed this up and demonstrated why this is the case, even with very significant storage, demand side measures or interconnection in support. There is a need to have a significant amount of zero carbon firm capacity on the system too - to supply dark, windless periods without too much reliance on unabated fossil. This firm capacity could be supplied by a number of technologies such as nuclear, biomass or fossil CCS

The Duck Pond Bonnie Marini; Power Engineering; 22 Mar 2016

The use of renewable power generation continues to grow around the globe. The challenge introduced with renewable generation is that it can be interrupted by timing and weather, and this variance affects the stability of the power produced. The sum of all generation must meet the demand at the very instant the demand is manifested-simply put, most of the electricity around the globe is produced and used in the very same moment. Without a solution for large-scale, cost-effective energy storage, the only way to fill the gaps in fluctuating generation from renewable resources is by partnering dispatchable power generation.
The California duck curve has become synonymous in the industry with the shape of renewable generation. The renewable duck generation rides on top of the rest of the generation portfolio, which is referred to as the duck pond. This paper discusses the changes in demand for this pond of dispatchable generating resources as they react to the presence and growth of the duck.

The Biggest Solar Breakthrough You've Never Heard Of William Pentland; Forbes; 12 Nov 2015

The breakthrough is a business model used to integrate distributed energy technologies into the mainstream electric grid.
For the first time in the history of the modern power grid, a non-utility, non-RTO entity called GridSolar is managing a part of the electric power grid. This would be illegal in any state other than Maine. GridSolar is demonstrating the value distributed generation, demand response and energy efficiency can provide to the power grid and ratepayers. In the process, it is turning the central argument made by utility trade groups against distributed energy on its head. Rather than imposing additional costs on ratepayers, distributed energy can significantly reduce the economic burden borne by ratepayers.

Balancing Europe’s wind-power output through spatial deployment informed by weather regimes Christian M. Grams, Remo Beerli, Stefan Pfenninger, Iain Staffell, Heini Wernli; Nature Climate Change letters; 17 July 2017

As wind and solar power provide a growing share of Europe’s electricity1, understanding and accommodating their variability on multiple timescales remains a critical problem. On weekly timescales, variability is related to long-lasting weather conditions, called weather regimes2, 3, 4, 5, which can cause lulls with a loss of wind power across neighbouring countries6. Here we show that weather regimes provide a meteorological explanation for multi-day fluctuations in Europe’s wind power and can help guide new deployment pathways that minimize this variability. Mean generation during different regimes currently ranges from 22 GW to 44 GW and is expected to triple by 2030 with current planning strategies. However, balancing future wind capacity across regions with contrasting inter-regime behaviour—specifically deploying in the Balkans instead of the North Sea—would almost eliminate these output variations, maintain mean generation, and increase fleet-wide minimum output. Solar photovoltaics could balance low-wind regimes locally, but only by expanding current capacity tenfold. New deployment strategies based on an understanding of continent-scale wind patterns and pan-European collaboration could enable a high share of wind energy whilst minimizing the negative impacts of output variability.

Weatherwatch: can we keep the lights on when the wind fails to blow? Kate Ravilious The Guardian; 9 Jan 2018

Rapid growth in both solar and wind (the UK now has more offshore wind power capacity than any other country in the world) has enabled the UK to achieve these impressive statistics, but will the rise in renewables also make UK power more vulnerable to the whims of British weather?
Researchers working on the European Climatic Energy Mixes project have been investigating future risk by assessing how the UK would fare with a repeat of the unusually cold winter of 2009-10. From mid-December 2009 a southward-displaced jet stream allowed cold air to pour in from eastern Europe, bringing widespread snow and plunging temperatures. The mean UK temperature for the entire winter was just 1.5C, the lowest since 1978-79 when it was 1.2C . As a result power demand surged, with electricity consumption between 10 and 20% above average on a number of occasions.
Back in 2010 renewables provided less than 10% of UK electricity. But similar weather now might create a strain. “The low wind conditions in a repeat of winter 2009-10 would lead to a substantial reduction in wind power production over the season, which could lead to increased risks to electricity supply availability when combined with an increased demand due to low temperatures,” writes meteorologist Emma Suckling from the University of Reading. Winters like this might be getting rarer, but we still need a contingency plan when the wind fails to blow.

China proposes $50+ trillion Global UHV grid connecting all power generation including massive wind farm at the North Pole by 2050 Next Big Future; 31 Mar 2016

China is proposing a $50+ trillion global energy grid. Global Energy Interconnection (GEI), a vision of a world power grid, was outlined by the State Grid Corporation of China ("State Grid"). It would be based upon a global network of Ultra High Voltage power lines connecting global power generation including massive wind farm at the North Pole and solar power from equatorial areas to energy users around the world.

China’s Vision of a Global Grid Zhenya Liu; The Energy Times; 22 Mar 2016

This is the first of a two-part series, excerpted and edited, from a speech by Zhenya Liu, chairman of the State Grid Corp. of China, delivered recently at IHS CERAWeek in Houston.




GHG emissions

Real greenhouse gas footprints of reservoirs revealed Science Daily; 4 Aug 2017

When hydropower reservoirs traps organic matter, it leads to higher local greenhouse gas emissions. But the emissions are not increased but displaced. A new tool calculates the real greenhouse gas footprints of reservoirs.

Impact on communities

License Denied To Brazil's Biggest Amazon Dam Sneha Susan John; Natureworldnews; 8 Aug 2016

Brazil's environmental protection agency has denied permission to build a giant hydroelectric dam in the Amazon rainforest because of how it could affect indigenous communities. Building of the dam can affect nearly 10,000 Munduruku people around the river Tapajós. This dam can flood a large area and might also lead to a forced removal of at least some indigenous communities. Removal of the indigenous groups is an act that is strictly prohibited by the Brazilian constitution. If the Sao Luiz do Tapajos (SLT) dam was built it would have been an 8,000-megawatt dam, the sixth-largest hydroelectric dam in the world and the second largest in the country. It was expected to cover a five-mile wide Tapajós river and drowns 376 sq km of the Amazon rainforest that hold thousands of people from indigenous communities.


Iraq's Mosul Dam could collapse at any minute 'killing one million people'

U.S. warns citizens to be ready to leave Iraq if Mosul dam collapses

Kariba dam's potentially catastrophic failure could have a deadly impact

Two of four damaged hydroelectric projects reopen in Brazil; 17 Mar 2016

Laos dam collapse: Many feared dead as floods hit villages BBC News; 24 Jul 2018

At least 20 people have been killed and more than 100 are missing in flooding following the collapse of an under-construction dam in south-east Laos.


Goring Weir hydro-power scheme given go-ahead BBC; 10 Mar 2016

Plans for a hydro-electric scheme on Goring Weir which could power up to 300 homes have been given the go-ahead. Goring And Streatley Community Energy Ltd want to put three Archimedes screws at Goring Lock to generate electricity.

Corwen Electricity Co-operative

We are intending to building a 55kW pelton turbine close to the centre of Corwen, which will be funded by community shares, and owned by the shareholders, who will automatically become members of our co-operative when they buy shares. Shareholders will get their capital returned over the next 20 years, and will get interest payments over this time, and some money will be put into a local community fund.

Justin Bowles comments in a thread on hydropower

The track record of community owned hydroelectric plans is abysmal. Almost none of them have hit their original targets and many of the early ones have a high probability of not being able to pay back their original shareholders and/or could go bankrupt.
The reasons for this are threefold: first the community hydro projects are almost all low river head projects. That is, their economic case is marginal to begin with. In general, the higher head projects have already been snapped up and developed by private land owners.
Second, the hydro consultants generally base generation numbers on far too optimistic assumptions. I am undecided as to whether this is due to a) wilful fraud (they get fat commissons for projects that go ahead, however 'doggy' they are or b) because they are basing their flow assumptions on historical river flow data that has been rendered unreliable by climate change.
People forget that hyrdo projects not only suffer from too little water but also too much. When their is a lot of water in a river, the head generally gets smaller. Given that we have been experiencing either feast or famine in river levels over the last decade or so, this is a major problem for projects that assume that most of the time the river is in the sweet spot of not too much but not too little water.
Third, 'shit' happens and this never seems to be conservatively accounted for in the generation numbers. And the 'shit' that happens can be monumental. You would think that the technology is pretty robust with a bloody great Archimedes screw or two and a generator. A common problem is that the intake mesh gets perpetually clogged, so you often need permanent volunteers to clear it of crap like branches or police cones that a passing yob may have thrown into the river. Given these projects have a 20-25 years life, you need pretty dedicated volunteers who are prepared to go out in mid winter to clear the crap away. Often their enthusiasm falls after a season or two. If you pay someone to do this it pays havoc with your returns. Worse, sometimes stuff gets through the grill and clogs the screw (like a dead sheep, I kid you not). Another problems some of these projects face is that the bearings go on the screw. That costs loads of money to fix.
There was one project, Stockport Hydro, that I thought was actually hitting its numbers and it even paid a dividend (they all promise to do this after a couple of years or so after commissing but few have actually had the money to afford a dividend). The the concrete plinth cracked holding one of the screws, so putting half of their generating capacity out of commission for a whole year. As I say, shit happens.
Finally, the number of these projects that flounder before build is huge. In the process, hardy bands of volunteers spend multiple years of their life for basically nothing. My heart goes out, for example, to Richard Riggs at Abingdon Hydro. Richard and the team spent five years and even got the share issuance away before eventually throwing in the towel. Here is Richard's sign off titled "Well We Tried".

Abingdon Hydro: Well we tried Abingdon Hydro home page; 3 Nov 2015

Vulnerability to Climate Change

Malawi suffers blackouts as drought exposes 98% reliance on hydro power Agence France-Presse; The Guardian; 8 Dec 2017

Large parts of Malawi have been plunged into darkness as water levels at the country’s main hydro power plant fell to critical levels due to a severe drought, according to its electricity company.
The impoverished southern African country which relies on hydroelectricity has been hit by intermitted blackouts since last year, but the outages have recently worsened, lasting up to 25 hours.
The state-owned Electricity Supply Corporation of Malawi (Escom) said on Thursday that power output had been halved as water levels in the Shire river dropped to critical levels.
The water from the river normally generates a total of 300 megawatts of electricity, which is 98% of the country’s supply. “For the past three weeks, the available capacity was 160 megawatts,” said Escom said in a statement.
Affected areas include large parts of the capital Lilongwe and in the second city of Blantyre.
A number of businesses and hospitals in the country had been forced to use diesel-powered generators to keep the lights on.

New Zealand Glacier Retreat will Impact Hydropower Mauri Pelto; From a Glacier's Perspective blog / AGU; 6 Jan 2017

Marine - Tide and Wave

Will Tidal and Wave Energy Ever Live Up to Their Potential? SOPHIA SCHWEITZER; Yale Environment 360; 15 Oct 2015

As solar and wind power grow, another renewable energy source with vast potential — the power of tides and waves — continues to lag far behind. But progress is now being made as governments and the private sector step up efforts to bring marine energy into the mainstream.

Tidal Energy / Tide Power *


Wave David MacKay; SEWTHA

Carnegie wave energy

CETO wave energy technology that converts ocean swell into zero-emission renewable power and desalinated freshwater.
Uses seafloor-tethered buoys. CETO 6 ~1MW will contain hydraulic - electrical generators, earlier ones seem to have had hydraulic to shore, electrical conversion onshore(?)

CETO commercial scale unit

The CETO 6 design builds on the experience gained in all previous CETO generations and incorporates some important improvements.
The diameter of the buoyant actuator has the most significant influence on power output and has been increased to approximately 20m from the 7m diameter 80kW unit successfully tested at the Garden Island site in 2011 (pictured below) and the most recent 11m diameter, 240kW units tested in 2015 at the same site (pictured below).
Apart from being larger, CETO 6 will also incorporate the power generation offshore, inside the buoy rather than onshore as with the current CETO 5 generation being deployed for the Perth Wave Energy Project. Locating the power generation within the buoy removes the need to attach pumps, accumulators and other hydraulic components to the seabed, avoiding the requirement for offshore heavy lift vessel capacity and reducing the offshore installation and maintenance time and cost.The demonstration of CETO incorporating subsea generation and transmission of electrical power will allow Carnegie to take advantage of deeper, more distant to shore wave resources and significantly increases the size of the commercial market for CETO and allow greater responsiveness in the CETO control system.
The Perth Wave Energy Project involved the design, construction and operation of three 240kW CETO 5 units which produced and sold both power and water to the Australian Department of Defence who operate Australia’s largest naval base, HMAS Stirling, on Garden Island and operated for over 14,000 cumulative hours across four seasons.
Work began in 2013 on the next generation CETO 6 design which has a targeted capacity of 1MW. The CETO 6 generation will again be demonstrated first at Carnegie’s Garden Island site in Western Australia ahead of international installations.


Eco Wave Power

talks about 1MW


Gibraltar wave power project surfs up possibilities across Europe Nnamdi Anyadike; Power Technology; 4 Oct 2016

Eco Wave Power’s (EWP) energy project in Gibraltar - the first such grid-connected plant and the only wave energy plant in Europe operating multiple units under commercial power purchase agreement (PPA) terms
in 2014, EWP signed a PPA with Gibraltar for delivery of a 5MW ocean power plant. Phased construction of the Gibraltar plant, located at the Ammunition Jetty, began last year and it is already exporting electricity into the power grid. The system is currently composed of eight ocean energy converter units that supply 100kW, but when completed, with the help of an EU grant, the array will produce 5MW. It is then expected to meet 15% of Gibraltar’s electricity demand. Although currently still in the design phase, the additional units will be much larger than the existing ones.


Biomass / Biofuels *


7 Steps to Build a Compost Water Heater For Hot Water Abundance KATRINA SPADE; Walden Labs; 5 AUG 2015


Urban algae farm eats highway pollution and turns it into organic fuel


New Zealand

Te Ahi O Maui geothermal ready to drill Gisborne Herald NZ; 28 Apr 2016

GISBORNE-based Eastland Group expects to encounter temperatures three times higher than the hottest surface temperature ever recorded on Earth when it drills into the Kawerau geothermal reservoir next month. Following years of planning, the $100m Te Ahi O Maui geothermal project to build a 20mW geothermal power plant 2.3km east of Kawerau is now ready to enter its first production well-drilling phase on land owned by the A8D Ahu Whenua Maori Trust. Te Ahi O Maui project panager Ben Gibson said site works were under way to prepare the well pads and a well-drilling rig would be transported on site later this month. A production well will start on May 10. The first stage of drilling, known as ‘‘spudding’’, will culminate in a 12cm-wide hole into the Kawerau geothermal reservoir. “Extensive field monitoring and computer-based modelling has shown we can expect the drilling equipment to pass through layers of varying substrates and pockets of incredibly hot geothermal steam and fluid, which could be between 200-350 degrees Celsius. “It’s this high-temperature fluid and steam that will ultimately fuel the geothermal power plant.

East Africa

How Kenya is harnessing geothermal energy to power its growing economy Amy Yee; Independent; 4 Mar 2018

Tapping into heat energy from the East African Rift has helped increase electrical access in Kenya. But making this widely available can be a struggle, and developers face environmental challenges with this seemingly green source of power


Heat energy beneath Glasgow British Geological Survey (BGS)

The BGS is working with Glasgow City Council to look into the use of heat energy from the ground to help to warm Glasgow's homes and communities.
Our studies are helping to identify which parts of the city would offer the best prospects of supplying this kind of energy; looking at the potential heat within minewaters, superficial deposits and bedrock aquifers beneath Glasgow.
This new source of energy could help Glasgow to meet government targets to ensure 11 per cent of heat demand comes from renewable sources by 2020.
It will also contribute to Glasgow's ambition, under the Sustainable Glasgow partnership, to become one of Europe's most sustainable cities within the next ten years. BGS expertise can help you find out more about the heat energy beneath Glasgow.