Agenda item

(1)          The Chairman welcomed Dr Melis and thanked him for agreeing to support the Select Committee process.

 

(2)          Dr Melis introduced himself, advising the Committee that he was a Senior Lecturer in the faculty of Engineering and Science at the University of Greenwich.  He was presently working on sustainable energy technology and how to improve their efficiency at a system level.

 

Question:  What are the challenges involved in Energy Storage?

 

(3)          Dr Melis explained that the need for effective storage was increased due to the inconsistent power generation of many renewable processes, for example solar and wind technologies being reliant on weather conditions.  Generation would peak during good conditions and drop at other times, requiring a good method of storing the excess energy to minimise the waste involved with such a peak / trough generation cycle. 

 

(4)          Dr Melis explained that a common problem was that energy storage was usually only developed on large-scale projects, such as hydro-dams.  This was further complicated by the fact that renewable generation could be set up more quickly than these large-scale storage systems could be put in place, leading to long periods of excess energy waste taking place prior to these storage systems coming online.

 

(5)          Dr Melis commented that batteries have long been considered the main alternative but they present their own problems given their limited lifecycle and disposal issues.  Batteries are also not necessarily suited to dealing with some of the large scale storage that is required.

 

Question:  How can Smart meters help?

 

(6)          Dr Melis advised the committee that Smart meters are beneficial in terms of informing energy consumers about their usage.  This form of communication between the supplier and consumer was an improvement as it replaced the quarterly bill with a process that allows consumers to easily monitor their usage and take action to minimise it for both financial and efficiency reasons.

 

(7)          Allowing the consumer to see their usage more real time increases the likelihood of more efficient energy use and greater uptake of efficiency measures such as insulation. However, the system as such had technical challenges that would not directly help the energy producers to more easily match generation and demand.

 

Question:  What is your view on fossil fuel generation?

 

(8)          Dr Melis provided an outline of the use of coal and gas, notably that coal achieves only 33% conversion to usable electrical power with the rest dissipated as waste heat.  Gas may achieve slightly higher levels, due to additional heat conversion processes able to minimise the wastage to bring overall efficiency for electricity generation up to around 60%.

 

(9)          Dr Melis acknowledged that coal and gas were still necessary at present but emphasised the need for reliable renewable alternatives to be identified.

 

Question:  How does government reconcile the expense of environmentally friendly forms of energy production with the high cost involved?

 

(10)       Dr Melis explained that as renewables represented a relatively new technology, the cost of such schemes still reflected more of the technology development costs.  As a consequence, the cost may be expected to drop as the technology becomes more mainstream and attracts more investment. 

 

(11)       Dr Melis commented that at present, there was little incentive for private sector investment so ongoing subsidies were required to maintain renewable schemes.  Dr Melis noted, however, that established renewables such as solar panels have seen a significant price drop over time which he expected to see in other technologies over the next ten to fifteen years if their uptake continued at least at current rates or improved further.

 

(12)       Dr Melis confirmed that there was a requirement to continue investment and research on renewables as fossil fuel resources were finite and that alternatives needed to be identified and made usable as soon as possible.  He appreciated that this presented financial and political challenges but urged that commitment to better energy use should be maintained and improved where possible.

 

Question:  Do energy generation operators know how to effectively measure excess?

 

(13)       Dr Melis confirmed that the Smart meter system would not be able to assist with real time measurement of use to ensure a better matching between supply and demand. 

 

(14)       He explained that the energy grid is currently regulated to stay within 5% of the 50 Hertz. The derivations versus this 50 Hz are currently used as a measure to identify whether there is a shortage of energy (lower than 50 Hz) or overproduction (higher than 50Hz). He advised that it was not always practical to cease energy production at short notice to minimise waste, an example being wind turbines, which are not capable of immediate switch-off. 

 

(15)       The key process was maintaining the grid at a reasonable level that bridges supply and demand, considering that both vary continuously.  Therefore, a better understanding of usage patterns could be beneficial to enable a better matching of supply and demand.

 

Question:  How can excess/waste heat energy be efficiently used in buildings?

 

(16)       Dr Melis explained that heat energy varies in usefulness depending on the temperature.

 

(17)       The need for maintenance and the different use of buildings, makes it challenging to ensure a 24 hour energy provision for any building, due to the fact that energy requirements move between office/commercial buildings and consumer homes within these 24 hours. He explained that certain systems can make use of heat energy to create electricity by using temperature differences to create an expansion cycle in an engine which then generates motion that can be converted into electricity, and these are the most promising technologies in terms of efficiency of conversion from heat to electrical.

 

(18)       Additionally, heat storage systems such as phase-change materials can be used to keep buildings at constant temperatures.  These materials change properties within a certain temperature range, which is when they store excess energy when available and release stored heat when required. 

 

Question:  What are your views on Fracking?

 

(19)       Dr Melis gave his personal opinion that while the potential energy resource return could be promising, the ecological and environmental impact of the process was too large and not worth the risk.

 

Question: Value of biofuel as a source of energy?

 

(20)       Dr Melis explained that some biofuel resources require significant land usage which can have a negative impact on food supply, while food supply is obviously more important considering the growing population, as has been clearly noted by the European Commission. When it comes to waste food, one can however make use of this in combination with an anaerobic digester to produce gas, which can then be used to generate electricity, as currently is already the case.

 

(21)       Dr Melis stated that the best way of looking at the energy generation issue was to consider how best to use as many of the various methods and systems in combination to achieve a good mix that minimises overall waste resulting while moving towards a truly circular economy.

 

Question:  Please provide further information on the Biofuel system used at the Medway Campus of the University of Greenwich

 

(22)       Dr Melis explained that the system had been set up following an extensive study of the demand profile to assess the required scale.  Issues such as what generation level to aim for (baseload or excess), storage options and capacity to import or export relative to demand all had to be considered prior to implementation.

 

(23)       The system set up produced 400kw of electricity via a CHP Diesel engine adapted to run on multiple fuels, with the aim of running it on Glycerol.  The process involved using a generator to produce electrical energy, with the engine’s cooling water used to heat up the water in the return cycle of the heating system before it goes to the boilers, which consequently reduces the heating contribution required from the boilers .

 

(24)       Challenges for the system included the sourcing of suitable Glycerol which is a by-product of the biodiesel manufacturing, but necessitates extra purification work to prevent excess salts from damaging the engine. Furthermore, Dr Melis commented that his University had other linked projects that look at alternative Glycerol supply chains that would alleviate this problem.

 

Question:  Feasibility of renewable technology for public transport?

 

(25)       Dr Melis explained that there were positive steps to take in promoting more efficient use of transport to minimise excess energy usage and waste but that this was dependent on consumer behaviour shifting in response to improved awareness.

 

(26)       Dr Melis emphasised that current alternative transport methods still relied on energy produced by conventional, non-renewable methods.  For example, electric cars still relied on power from the main grid which was maintained through fossil fuel usage.  Consequently, it was crucial to develop technology to ensure sustainable renewable energy production at required levels before considering the use of electricity as the main source of energy for transport.  As a consequence of this, most public transport improvements based on electrification are not sufficiently thought through and would not achieve significant energy efficiency or environmental benefit.  Examples raised by the Committee such as the Japanese bullet train model that uses magnetic forces were discussed in terms of the very high energy usage required that could undermine the benefits of the technology.

 

(27)       Responding to questions from the Committee regarding High Speed Rail, Dr Melis commented that the high energy requirements meant that there was a risk of exceeding supply if demand levels were not properly assessed.  Additionally, there were technical issues to be considered such as the capacity for generators to bridge the supply / demand gap when necessary as was the case for the London Underground.  However, such generator systems are very expensive and rarely used, making them not particularly cost effective.  All these considerations made the project a complicated matter from the point of view of energy management.

 

Question:  Will the challenges of effective energy storage be overcome in the near future?

 

(28)       Dr Melis advised the Committee that the success of future development in the area of energy storage was dependent on investment, as with other areas of research.  He explained that the storage market had been content with batteries for so long that innovation had stagnated and no solution to larger scale situations had been developed.

 

(29)       Alternatives to batteries being researched included hydrogen and compressed air.  The problem with hydrogen was that it has a round trip efficiency of around 40% while batteries achieve 80% and upwards.  Compressed air, which produces heat on compression and requires heat during decompression, had potential as it seeks to address heat and electricity production/use together, creating a less wasteful energy cycle. However, this requires energy demand was being looked at as a combination of heat and electrical, which are required in most situations, but rarely looked at in combination. 

 

Question:  What are the main issues facing the UK energy landscape?

 

(30)       Dr Melis advised the Committee that long term strategic planning was required, instead of the more common short term, quick fix approaches currently being taken.  He emphasised that much more work needed to be done on identifying better sources of energy rather than just minimising waste or pollution from existing sources.  Additionally, consumers needed to be better informed about their usage so that demand could be better managed in the future through more responsible consumer behaviour.  This was also linked with promoting the concept of individual responsibility and helping to make a difference, as many people seemed to not bother to change behaviour due to a perception that their energy use was negligible compared to nations or corporations.

 

(31)       Responding to Member questions about pricing incentives, Dr Melis suggested that increased pricing based on usage would encourage lower demand and should not be detrimental to businesses as they could tailor their processes to use less energy as a result.

 

(32)       Dr Melis suggested that greater investment in energy research would be beneficial to the UK as further development would reduce renewables technology costs and speed the development of reliable and sustainable alternatives to fossil fuels. These developments should comprise looking at the overall picture, with electrical and heat energy in terms of generation, storage and consumption.

 

(33)       The Chairman thanked Dr Melis for his contribution to the Select Committee.