Baseload: overrated?

Talk renewables and the first doubt voiced is how do we address the intermittency issue? Inevitably one looks for baseload! Who better than Germany to ask! How did Germany switch over directly from nuclear to renewables without first relying on ramped-up coal use during the transition? As a new study shows, renewables completely ‘obliterate’ the need for baseload power. The study’s main question was: How will intermittent wind and solar power affect the grid? And how much electricity will need to be stored?

Dispatchable power generators will mainly have to be flexible, but this requirement can be met in all of the scenarios. And up to a 40% share of renewables, the cost of power storage (or otherwise lost excess power production) remains moderate, only raising the cost of power by 10% in the worst case, Renewables International says.

Renewables International had already found based on its calculations that Germany won’t need to make any real changes to its grid and won’t need very much power storage if it meets the targets that it currently has set for wind and solar. If the targets are met, Germany will get around 40% of its electricity from renewables. As a comparison, it got around 25% of their electricity from renewable sources during the first half of 2012. So far, the effect has mostly been to offset power from natural gas, but it’s been increasingly “cutting into the baseload.” Denmark, which is already sourcing over 40% of its power from renewable sources, hasn’t had to create any major power storage infrastructure so far.

To move beyond 40% to 80% renewable power (the target for around 2050), Germany could need as much as 14 GW of short-term and 18 GW of seasonal power storage to meet its peak power demand of around 80 GW in the moderate scenario. At that point, power prices would be roughly 10% greater than in 2011, but reaching 100% renewable power will be quite expensive indeed. The German engineers estimate that the final 20% will triple the need for power storage, raising prices once again by around 19%. Not only will nuclear disappear but coal power use will fall off, nearly disappearing by the time the country sources 80% of its electricity from renewable sources.

The country’s phaseout of coal power is based not on an official policy, but rather on a general understanding among experts in the power sector that the switch to renewables will gradually obliterate the need for baseload power, says the study. And if Germany can do it, any reason why others can’t?

A load off the clean energy basket

Time and again one comes up against the debate on baseload, how important is it for energy security? Not at all, say experts. The entire US grid could be powered by just wind and solar thermal, they say, challenging the very concept of baseload power, the sort provided by coal and nuclear.

Grids can work perfectly well with a mixture of inflexible supply like wind and flexible supply (solar thermal with storage). Wind is already cheaper than new-built coal in the US, and solar thermal with storage, and used as a peaking plant, will be competitive with peaking gas, they say.

PV also has the same impact as wind. As wind and PV fills up the energy stack (they go first because they have the lowest short run marginal cost), what is needed to complete the requirements is flexible generation. Not coal, they say.

This is seen in South Australia, where wind has provided more than 20 per cent of annual output last year and much higher on occasions. In Germany, where wind and PV capacity amounts to 45GW, Statkfraft has announced this week that it may close two gas-fired power stations, amounting to one gigawatt of capacity, because of this impact.

So what holds up the rest of the world, so unwilling to let go fossil fuel and come clean? Apathy largely.

Base bias

We all pay much heed to baseload power and the need to have some source catering to that need. But some people like David Mills believe baseload can be dispensed with. The eminent solar energy technology developer, has dreamed of creating a new model for an energy system that does away with the conventional design of massive baseload infrastructure. Using hourly data for energy use of the entire United States economy in 2006, Mills will demonstrate how it could have been powered almost exclusively by wind and solar.

The traditional paradigm of flatline baseload does not exist in Mills' scenario, but the replacement for baseload power is not another baseload, it’s a system of flexible and inflexible energy mechanisms based around wind and solar and other sources.

The first premise was that there was enough solar and wind that, in combination, could run the US economy. The second was that solar and wind would be connected with a new electricity transmission system, using high voltage direct current lines for the spine of the network, which will allow more flows and result in considerably reduced transmission losses.China is installing more HVDC lines than any other country in the world – looking to link coal plants with the Three Gorges dam and wind and solar from the north and west of the country!

Any opinions?