Renewable Energy

UK has access to extensive wave power resource, particularly in the areas of the north, north west and south west with high energy wave environment. Wave energy availablity is highly seasonal, exposed to seven times more energy in winter times compared to summer, when electricity demand is high. At national level the areas that need transmission, developing combination of wave and tidal resources smoothes variablity and supply. Almost half of the wave power available annually around the UK occurs during December, January and February.

The UK tidal stream resource is site-specific and dominated by two superimposed cycles. The semi-diurnal cycle (two high tides and two low tides per day) is unique to particular sites, and sites may be out of phase with each other. The spring/neap cycle on the other hand, (which repeats every 14 days, and has the effect of increasing peak velocities in both ebb or flow), occurs at all sites simultaneously.

Tides are driven by gravitational and rotational forces between earth, moon and the sun causing water on the surface to move. These movements are predictable. The timing of high and low tides is affected by location. The output of tidal power systems can be predicted many years in advance, allowing future electricity output to be accurately known.

A long term energy security requirement needed investigation of characteristics of the overall marine energy system to determine the future of marine renewables in the UK. Waves can be genreated in different ways but waves generated by the action of the wind on the surface of water is important for electricity generation. By examining the hour to hour fluctuations of the wave power, the variability can be assessed.

Graham Sinden of the Environmental Change Institute at Oxford University said the results showed wind patterns in Britain were not randomly distributed but were clearly concentrated at certain times of the day and year.

These findings undermined one of the main arguments against wind turbines - that the power generated from them is intermittent and unreliable.




Source: Oxford Univ. Environment Change Institute, www.eci.ox.ac.uk
http://www.carbontrust.co.uk/NR/rdonlyres/EC293061-611D-4BC8-A75C-9F84138184D3/0/variability_uk_marine_energy_resources.pdf


Measuring Consumption

Informative billing initiatives in Norway showed how customers appreciated improved accuracy and extra information (historic and comparative feedback, a guide to which end-uses were the highest consuming), began to read their bills more frequently and with more understanding, and began to alter their behaviour (Wilhite 1997; Wilhite et al, 1999). Various qualitative studies (eg Egan 1999, Roberts et al 2004) give more detail on how customers respond to different billing designs. The latter deals with UK billing and shows some distrust of comparative feedback: customers were suspicious about the validity of their comparison group but appreciated feedback that compared their recent consumption with that in previous billing periods.

As the literature on feedback expanded, so did that on energy use and on measures to reduce consumption and promote efficiency.

Feedback with various degrees of immediacy and control by the user:

Direct feedback: available on demand. Learning by looking or paying
• Self-meter-reading
• Direct displays
• Interactive feedback via a PC
• Pay-as-you-go/keypad meters
• ‘Ambient’ devices
• Meter reading with an adviser, as part of energy advice
• Cost plugs or similar devices on appliances
Indirect feedback – raw data processed by the utility and sent out to customers.
Learning by reading and reflecting
• More frequent bills
• Frequent bills based on readings plus historical feedback
• Frequent bills based on readings plus comparative/normative feedback
• Frequent bills plus disaggregated feedback.
• Frequent bills plus detailed annual or quarterly energy reports.
Inadvertent feedback – learning by association
• With the advent of microgeneration, the home becomes a site for generation as well as consumption of power.
• Community energy conservation projects such as the Dutch ‘Eco-teams’.
Utility-controlled feedback – learning about the customer
• Utility-controlled feedback via smart meters, with a view to better load management.
Energy audits – learning about the ‘energy capital’ of a building
Audits may be
• undertaken by a surveyor on the client’s initiative
• undertaken as part of a survey for the Home Information Pack
• carried out on an informal basis by the consumer using freely available software, eg carbon calculators.

Source: www.eci.ox.ac.uk