Collecting data to design the energy system
This stage follows Project Definition and is followed by Energy System Design
Following the selection of technologies to be considered for the renewable energy system the relevant data now needs to be gathered in preparation for evaluating and designing these systems. This may include (but is not limited to) technical data such as climate data, biomass resource and housing stock as well as social data such as community population and current energy use.
As this methodology addresses issues that may be faced when designing an energy system for a remote community, it is important to consider methods of data collection. Since it is more than likely that the location of interest has not been extensively studied, this poses many challenges when trying to collect technical data for the design stage.
This stage of the methodology will address these issues with procedures to help obtain better estimates for technical data and is broken down into three steps:
The climate data that is required will predominantly depend on the software to be used for modelling the energy system. This usually consists of temperature, solar (diffuse horizontal/direct normal) irradiance, wind speed and relative humidity throughout the year. These parameters will help with the estimation of the resource available for the energy system as well as define the current outdoor conditions for heat demand optimisation.
Furthermore, social data on the village should also be considered in this stage as it may have major implications on the type of energy system that is chosen for the village. For example, the social structure of the village may help decide whether the system could be communally owned or whether it would be better to implement an independent system for each household. There may also be fluctuations in the village’s population over the year that may affect the electrical and thermal demand of the village. This too can have implications on the chosen system. This can be for a variety of reasons; such as climate conditions, economics or simply cultural practices. Many projects fail due to the lack of understanding of the community’s cultural practices that may be affected by the introduction of a system.
It is highly challenging to find comprehensive climate data for remote villages, as these areas are often not as extensively studied as communities in developed countries. The best data source would be if there are local weather monitoring stations nearby, then it may be possible to obtain basic data on the climate throughout the year. Although this may be enough to design a system with some commercial software, research software usually requires an input of hourly recorded data, and local weather stations may not provide such detail.
If local weather stations are not available or provide insufficient data, there are national databases of hourly climate data available for research use, such as the National Renewable Energy Laboratory (NREL), who have an extensive database of hourly recorded climate data from many parts of the world.
Screenshot of PVSyst Software
Depending on the proximity of the national database source to the location being studied, the trend of the data may be similar as both locations go through similar seasons. However, although national database would depict the stochastic nature of the climate of a country, it may not be sourced close enough to the site of interest to accurately portray the climate, as there are multiple parameters that could affect such data (for example, elevation and topography). Therefore, it may be necessary to transform this data to better represent the climate of the location being studied and produce more realistic results for the energy system design inputs.
If topography is expected to have a significant effect on the solar resource available, modelling software such as Meteonorm or PVSyst (pictured right) can be used to map the landscape and estimate how much solar resource the village would receive throughout the day. Solar paths are the movement of the sun across the sky throughout the day. This will change depending upon the time of year with solar declination. The solar path will be obstructed (with respect to the view from the point of study) by the horizon at different times depending if the terrain is flat or mountainous.
To estimate river resource to determine the hydropower potential for the village, Google Earth Pro is a useful tool to estimate the head available along a nearby river, as there is often little to no data on such parameters. Flow rate could be measured on site, however if this is not possible it could estimated by looking at data from similar rivers.
Finally, biomass resource available is best collected by carrying out surveys on the current resource used for cooking and heating to gain an estimate of how much is available in the community. As information such as biomass usage and available materials is more easily known, this can be directly obtained by speaking to a local from the village being studied. It is possible to estimate the village’s available resource by looking at what they are currently using in terms of crop and livestock, as well as the amount of waste produced and nearby forestry available. The types of materials that could be locally sourced would also be of use for the demand optimisation of the village
To see the results of data collection for the case study in Pangboche click here
The next step of the methodology is Energy System Design