Energy

If the United Kingdom needs to build more Power Generating capacity should solar PV be a priority ?

 

The Department of Energy and Climate Change supports Solar PV projects subject to Four Guiding Principles

1) Support for Solar PV should allow cost effective projects to proceed and to make a cost-effective contribution to UK carbon emission objectives in the context of overall energy goals.

2) Support for Solar PV should deliver genuine carbon reductions that help meet the UK’s target of 15 per cent renewable energy from final consumption by 2020.

3) Support for Solar PV should ensure proposals are appropriately sited, give proper weight to environmental considerations such as landscape and visual impact, heritage and local amenity and provide opportunities for local communities to influence decisions that effect them.

4) Support for Solar PV should assess and respond to the impacts of deployment on :  grid system balancing ; grid connectivity ; ensuring that the challenges of deployment of high volumes of solar PV are met.

 

 

Photovoltaic (PV)  solar panels  are a less cost effective source of generation per unit power as shown in the links below.  This does not take into account that solar is an intermittent source and capacity would need to be duplicated in another technology further decreasing its cost effectiveness.

Independent bodies tend to show that large scale solar farms are one of the least cost effective sources of green energy generation. Here are some  examples.

 

Internal analysis of Recycled Energy Development LLC

http://blog.recycled-energy.com/wp-content/red_generation_costs.jpg

 

California Energy Commission, “Comparative Costs of California Central Station Electricity Generation.

http://www.renewableenergyworld.com/assets/images/story/2010/12/8/5-1332-the-true-cost-of-renewable-energy.jpg

 

EIA, Levelized Cost of New Generation Resources in Annual Energy Outlook 2013

http://aweablog.org/uploads/images/EIA%20Levelized.png


 
Solar demand : capacity

Graph – BRE NSC Roadshow National grid showing how up to 10G W can be accommodated now.

 

The above graph shows varying amounts of power generated and consumed in Giga Watts against time of day in July when solar power generation is at its maximum.

The dark thick plot 0 GW at the top indicates how demand varies through the day using the minimum load model.

The rainbow of plots 1-25 GW shows a range of possible contributions by solar PV generation deducted from that demand.

The area below each plot (mostly white) therefore is the power that would still need to found from other non solar PV sources (all night and less during the morning and evening but still some all through the day). Solar PV is not contributing enough power in the evenings resulting in this missing capacity needing to be provided by gas power plants to balance supply with consumption duplicating the necessary investment.

Note that the area of the rainbow is dictated by the weather and the seasons and that the graph shows July where a maximum of 17 hours of daylight might be expected (or not)  and showing contribution by solar PV at its best.

Imagine the smaller area of the contribution from the rainbow plots in winter when 8 hours of daylight or less occurs and when demand is much greater.

Because solar PV is an intermittent source of large scale generation, solar PV generating capacity would also need to be duplicated with  alternative 24/7/52 sources. This suggests that large scale solar PV should have a low priority compared to those 24/7/52 sources and is not a cost effective solution as it duplicates costs that will have to be spent whether one has solar PV or not.

The graph shows that Solar PV may be useful for consumers who wish to reduce their bills and run appliances during summer sunny days and is well suited to small scale installations.

 

Are Solar Photo Voltaic (PV) Panels Green ?

The graph below shows that solar power has one of the higher CO2 emissions per unit power produced (when the amount of energy required for the construction of photovoltaic (PV)  solar panels  is taken into account).


CO2perKWH-5 copy

This information is available in the Palace of Westminster where few are qualified to respond to proven truths

http://www.parliament.uk/documents/post/postpn_383-carbon-footprint-electricity-generation.pdf

The energy yield ratio (the ratio of the energy delivered during its life time / to the energy required to make it) for a  grid connected solar PV system in central northern Europe with a life time of twenty years is just 4  compared with 80 for Wind turbines. For panels manufactured in China using coal generated power this aspect can not be ignored when calculating carbon savings. Often  the output from PV Panels  is claimed as a befit in offsetting against carbon emitting generation without balancing the emissions caused by PV panel manufacture.

As coal powered generation has reduced significantly now and will reduce further in the next few years it will be harder for solar PV to demonstrate significant  ‘genuine carbon reductions’.


Will Somerton Door provide the power output claimed ?

Output estimates for Somerton Door Solar Farm
1 hectare = 10 000 square metres
Solar farm area 18 hectares = 180000 square metres of site
Area of grassland is 29 of the 42 acres of the site therefore
Area of panels is 13 of the 42 acres of the site
 13acres/42acres = 0.30952381 55714 square metres of panels
10% efficient panel Av Watts 612857 .@11W/m2 average power output Cheap panel
20% efficient panel Av Watts 1225714 .@22W/m2 average power output Expensive panel
10% efficient panel AV Annual W 5369 MWh/Y
20% efficient panel AV Annual W 10737 MWh/Y
Light source Claimed Annual Output is achievable 7065 MWh/Y
Conclusion
It is unusual for Solar Farms to invest in high efficiency panels because of the increased cost so  the claimed power output may be optimistic.

For figures used in calculation see

http://www.withouthotair.com/c6/page_39.shtml

http://www.edfenergy.com/energyfuture/energy-gap-quantity/solar-and-the-energy-gap-quantity

http://www.solarpowerportal.co.uk/news/if_solar_covered_one_percent_of_the_uk_it_would_meet_the_countrys_2356

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/249277/UK_Solar_PV_Strategy_Part_1_Roadmap_to_a_Brighter_Future_08.10.pdf

http://2050-calculator-tool.decc.gov.uk/pathways/11111111111111111111111111111111111111111111111111111/primary_energy_chart