PV2025 - Potential Costs and Benefits of Photovoltaics for UK-Infrastructure and Society

The installation of photovoltaics today is largely evaluated in terms of quantity and the success of any market stimulation evaluated on the basis of how well the targets are met. This may cause significant problems for the national infrastructure and may lead to significant unnecessary costs for grid stabilisation. However, these factors are sometimes assessed too simplistically. When considering PV in a national context, it is also largely seen as a homogenous swarm of devices, i.e. all of them reacting rather similarly. This does not consider different orientations (system elevation determines the seasonal maximum, system orientation determines the daily maximum) or regional differences in the environmental conditions such as weather fronts passing in a matter of days over the country rather than instantaneously or the North experiencing a different weather front than the South; nationwide smoothing might very well limit the need for power control. Thus the overarching question in this proposal is 'How can we maximise the benefits and limit the costs for UK plc while having a vibrant PV market?'. The work is split into four topical areas (work-packages), which answer the four key questions:
- How much PV are we likely to get with different policies and where is it likely to be installed? This will consider different socio-economic drivers, cost curves of PV and work on installation scenarios giving links to likely social background of installations, locations (as in regions) and quantities.
- How much energy will this generate when and where? Based on current installations a model for the performance prediction of systems based on their post-code will be developed and validated against existing FIT data and other available monitoring data. A spin-off of this activity will be the widespread investigation of current installations, that will inform any further discussions on subsidy streams, and the potential for detailed condition monitoring with sparse data will be investigated. The model will be connected with the socio-economic drivers to stochastically locate future installations (using GIS and post-code classifiers), and estimate the energy yield for each system and aggregate to generation regions. This means that essentially for every system (which is today in the range of 400000 systems under the FIT) installed an hourly generation needs to be calculated, which will require very complex speed optimisation in the calculations.
- How will it impact the infrastructure? Grid simulations will be carried out bottom up as well as top down to see if there are issues either locally or nationally with the proposed installations. This will allow the recommendation of further measures to strengthen infrastructure and will allow a cost-benefit analysis of PV technology to be undertaken.
- What feedback will there be? Most policies will have effects on the questions above and thus it is foreseen that a feedback methodology will be created, calculating the costs/benefits for UK plc as well as evaluating likely responses of the policy makers and grid operators.
The collaboration between the different groups will be tightly managed, so that the project outcomes interface well. Tools will be generated and made available with non-proprietary data for public use.

The impact of generating understanding is notoriously difficult to quantify. This project will help in avoiding problems and to accelerate implementation of PV in the UK in a way that is in the best interest of UK plc. A major effect could be on optimised regulation and energy maximisation.
To demonstrate the impact this may have one could consider a situation as in Germany where systems are now only allowed to deliver 70% of their rated power, i.e. they can deliver all the power they are capable to deliver up to 70% of the rating and must be regulated down beyond this point. This will cost annually 15-20% of energy production. In the UK this would waste around 320M£ per year (assuming systems yield of 800kWh/kWp, average FIT/ROC around 0.2£/kWh and current installed capacity of 2GWp). Should this project allow avoiding such a situation, there would be an enormous financial benefit for UK plc. This is just one example illustrating that interfacing effects add up very quickly to significant costs, much larger and much more nationally relevant effects then e.g. changes in production technologies. This is a national issue as countries have different power systems. Identified issues with high penetration may thus not be relevant to the UK in that form. Thus developing a high-resolution generation model will very significant impact in terms of avoided costs in the medium term.
Benefits such as fuel-poverty-alleviation or strengthening of weak grids or injection of reactive power are not currently quantified or realised to their best potential. This project will deliver the tools to do so and thus allow a much more holistic approach in assessing the market penetration of PV technologies. It will allow the quantification of the benefits in much more detail than before. The combination of this engineering based work will enable a much more science-based discussion of different installation scenarios and will identify the need for investment into the infrastructure. This would then minimise the risks of 'brown outs' as seen in the US where not enough power is generated, or negative costs of electricity as seen in Germany, where at certain times (admittedly rarely so far) the cost has been negative in the electricity exchange and people were actually been paid to consume power. The costs of these grid 'mishaps' are very difficult to quantify, but if the project could just help to avoid a single such incidence, the cost savings would be orders of magnitude larger than the funding requested.
The project will not only answer engineering questions, it will also provide answers for the questions of 'how do we get there?' and 'what if we try to use this feedback?'. These questions will be essential for policy makers and decision makers in the various companies involved with the grid management. The impact here will be in better informed policies, which should enable an accelerated and hopefully appropriately financed deployment of PV to achieve the maximum benefit for UK plc. It is difficult to quantify this effect but again the impact should be rather significant.
There will be also impact in terms of new commercial services for the supporting companies. EOn will benefit from better understanding the pricing strategies of PV and operation of their PV systems. As a retailer of solar systems, they could also offer performance monitoring as part of their FIT package, which should make them a more attractive FIT provider and thus increase their business. Bluesky will consider offering further services based on the GIS work of this project as this would present a natural extension of their current 'find a roof' service. Housing assosciations will benefit in being able to argue the case for PV in a social fashion.