Overall, project investigation revealed that adding PV to an existing
Wind farm isn’t an effective way to fill the power generation gap. It is
however possible to effectively utilise the physical space between the turbines
with PV panels.
The project didn’t reveal any major technical barriers to prevent the installation
of PV panels into an existing wind farm – it simply uncovered that it isn’t the most
effective way of addressing the problem of wind power variability and current economic
factors make it financially unattractive.
Read on for more specific feasibility conclusions in the sections below.
Shading
The analysis has proven that even for a tough scenario there is still plenty of space to install PV panels without significant losses. This works very well especially when the land belongs to a developer and so the cost related to losses are lesser than cost of leasing the land at most of the spots.
Northern summer shadows are the ones responsible for major losses; fortunately summer shadows are way shorter, so most of the area is unshaded during summer. Winter shadows despite their length won’t really affect yearly output first of all due to lack of sunny days in winter and secondly due to smaller amount of time the sun might provide energy.
All in all for a real case the results would be even more promising. Complexity of wind turbine model simulation in the software forced us to use a conservative model; also spacing of the turbines was at its minimum. More detailed please look up the shading section.
Full details of how this conclusion was reached can be found in the Shading main tab.
Climate
The key element of this project was getting a healthy data to work with.
It was easy to get "Velocity Exceedence Curve" for locations around the UK
which is widely used in the business. Unfortunately this data was useless for
our project, since what we needed to see was the correlation between the hourly
power outputs of a wind turbine and a PV panel in a certain location. The problem
with obtaining this data is, it needs real time on-site wind speed measurements for
a long period of time and then sensitive calculations to create an average to create
this data. It is a hard work that takes long time which results with it being really
expensive. We had extremely hard time to obtain this for free with no chance. In the
end we used Strathclyde own ESP-r software to obtain the data we needed for 11 different
locations in the UK. The problem with doing this was, conditions were always ideal,
so wind turbine was generating max power output for most of the time. In real life,
most of the wind farms perform less then their predicted outputs. In the end we
realized that a project like this would be more successful if it was applied to an
existing underachieving wind farm which has a real time power output data at hand.
Full details of how this conclusion was reached can be found in the Climate main tab.
Output
Due to the positive feedback between the general pattern of the wind and solar
resource in the UK according to the data available for use in this project,
the addition of PV panels at an existing wind farm location isn’t the most effective
way to fill the power generation gap.
Whilst small quantities of PV panels can create a small improvement in grid capacity
utilisation, this is insufficient to offset the financial investment required. Adding
increasing quantities of PV panels, whilst improving the PV contribution, very rapidly
increases the proportion of this additional resource which is wasted. Since one driver
for introducing PV was the desire to improve and smooth out energy quality characteristics,
introducing over capacity generation with the control systems complexities this brings
would seem illogical in the extreme.
Full details of how this conclusion was reached can be found in the Output main tab.
Finance
In order to announce this project feasible, it has to be economically viable and profitable.
This is translated to IRR=10%. The results from the financial analysis demonstrated the opposite.
Unlikely the major advantage of utilising the same land and grid connection is not adding noticable value
to the project's economics. The three most influential factors regarding the IRR are the level of subsidy, the cost of the
technology and the efficiency of the technology regarding the annual output.
Even when a best case scenario is occurring, the economics of the solar farm do not indicate the
stakeholders to invest into that concept(PV/Wind). This is mostly caused by the recent reform of the solar
market.
Although the particular project is mostly never responding to the expectations of the stakeholders,
other alternatives might by the case for reversing the undesirable outcome, such as another location, small
sized solar schemes etc.
Full details of how this conclusion was reached can be found in the Finance main tab.