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Tag Archives: Supergrids

Are we really all going to go off grid?

By Dave Elliott

In 2014, the US Rocky Mountain Institute (RMI) released a ground-breaking analysis of the potential for ‘grid defection’, looking at when and where it might be economical for customers to disconnect from their utility in favour of using on-site solar-plus-battery systems. With PV solar and batteries getting much cheaper since then, it has become a hot issue. However, fully off-grid options still seem unlikely to be attractive or needed for most people – a grid link allows you to top up when there is a solar input lull and your battery is drained, and to sell any excess at other times. In the US this “net metering” approach is quite widespread, although there are disputes about the prices paid by utilities. In the UK the FiT system has an export tariff. Will consumers be willing to forgo that? Would that be wise? (more…)

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What sort of green grid system?

By Dave Elliott

It’s clear that we will need energy transmission grids and networks to help balance variable renewables and link up locations where there is excess to areas where there are temporary lulls, but what sort of energy is best for transmission? And for storage? Both are important and can interact: in some cases storage may be better as a local option than long distance transmission, while in other cases, long distance transmission may allow access to areas where storage (e.g. pumped hydro reservoirs) is easier.  However, electricity isn’t necessarily always the best option for either: for example, gas can be transmitted long distances with low losses and, once installed, gas pipelines are less invasive than power grid tower links. Gas can also be stored in bulk in underground caverns and the gas grid itself is a store. So as we move to a new energy system, we need to think about all the possible energy vectors – and that also includes heat.

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Greenpeace – 100% global renewables by 2050

By Dave Elliott

A new report from Greenpeace says the world can be 100% renewable in energy by 2050, and 65% renewable in electricity in just 15 years. The 2015 Energy [R]evolution report, the latest iteration in its global and local scenario series, says global CO2 emissions could be stabilized by 2020 and would approach zero in 2050. Fossil fuels would be phased out, beginning with the most carbon-intensive sources. (more…)

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Energy storage – new ideas Part 1

By Dave Elliott

Energy storage is usually seen as a very good idea – it would help cope with variable renewables. Indeed some enthusiasts now even say that cheap battery storage will make PV solar so viable at the domestic level we may not need grid power!  Or even grids!  That seems unlikely – they help to balance variable demand  with  supply  from a range of sources near and far. But one thing is clear – energy storage, large and small scale, is becoming a big issue, with many new ideas emerging.    (more…)

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Smart meters and smart grids

By Dave Elliott

The newly emerging energy system will need new grids of various types. In my previous two posts I looked at international low-loss High Voltage Direct Current supergrids, and suggested that though they may well be developed in the years ahead, the process could be uneven and incremental, starting with local/national smart grids designed to aid local balancing of variable supply and demand. (more…)

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Supergrid (2) – could it work?

By Dave Elliott

In my previous post I looked at the potential and problems of supergrids. The basic idea is that, since, in various parts of the EU, there will be times when there is excess electricity generated from wind etc. over and above local demand, this excess can be shunted to regions which are short and have high demand, using low-loss HVDC supergrids. Would it work on a large scale?

(more…)

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Supergrids – a desert mirage?

By Dave Elliott

There have been reports that the Desertec Industrial Initiative (Dii) had abandoned its plan to help support the development of solar power in the Sahara and the export of some to Europe, since it looked as if the EU could meet most of its green energy needs indigenously, without significant imports. So is the desert CSP/supergrid idea dead? (more…)

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Balancing variable renewables- capacity markets, smart grids or super grids?

By Dave Elliott

The previous few posts have looked at the state of play with renewables in some key countries. In many cases an urgent issue is grid integration and balancing. The variable outputs from wind and PV solar outputs are balanced on some grid systems by using existing fossil-fueled plants, but the later are having a hard time competing, now that some of their peak market has been taken over by low marginal cost (zero fuel cost) wind and PV. To ensure that there is enough capacity still available capacity markets have been proposed, offering extra payments. Some critics don’t like the sound of that- it’s yet another subsidy, in effect for fossil fuel. However, the proposed UK version includes payment for energy storage and demand management options, as well as for gas-fired back up plants, and longer term, fossil gas might be replaced by green gas in the latter. There again there are other balancing options- supergrid links for example, which would open up a new multi-national balancing market.  Which option is best? (more…)

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Wiill the lights stay on?

by Dave Elliott

There has been a long and sometimes heated debate over UK grid security issues, with some claiming that the spread of wind power and PV will undermine it.  Ofgem’s 2013 Electricity Capacity Assessment says ‘Wind generation, onshore and offshore, is expected to grow rapidly in the period of analysis and especially after 2015/16, rising from around 9GW of installed capacity now to more than 20GW by 2018/19. Given the variability of wind speeds, we estimate that only 17% of this capacity can be counted as firm (i.e. always available) for security of supply purposes by 2018/19.’ https://www.ofgem.gov.uk/ofgem-publications/75232/electricity-capacity-assessment-report-2013.pdf

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Green energy in China

By Dave Elliott

China is pushing ahead with renewables on a very large scale, with renewables and other non-fossil fuel options expected to provide around 15 % of its total energy needs by 2020: the nuclear programme is a small part of that, aiming to get to 4% of electricity by 2020. Renewables already supply 17%.

Wind power is the big new thing. There is 62 GW of capacity installed so far- way ahead of every other country. And that’s just the start. The Chinese Wind Power Development Roadmap 2050 stipulates that China will have 200 GW installed wind capacity by 2020, 400 GW by 2030, and 1,000 GW by 2050.

However, it is trying to refocus what has so far been something of a uncontrolled boom, with, for example, insufficient attention having been paid to proving the necessary grid links. The result has been that, although China had over 42 GW of wind capacity installed by the start of 2011, only an estimated 31 GW was grid-linked. Many of these projects, most of which were in remote areas in the North West, poorly served by grid links, were often unable to dispatch their full potential output to users, most of whom are in the major urban areas on the coast. This issue is now being addressed- the 12th Five-Year Plan period (2011 – 15), includes significant investment in grid infrastructure.

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