Frequently asked questions

Q) What is the mini-grid-builder?

A) The mini-grid-builder is an online tool for engineers, project developers and investors willing to develop mini-grids. The tool provides a framework for data collection and calculates the effective demand based on a complex algorithm to size and design solar hybrid mini-grid systems.


Q) What does solar hybrid mean?

A) Solar hybrid means the generation of electricity with photovoltaic modules combined with another power generating energy source. This conjunction creates a generation of electricity with low greenhouse gas emissions and a high security of supply.


Q) What is a mini-grid?

A) We define mini-grids as involving small-scale electricity generation, and the distribution of electricity to a limited number of customers that can operate in isolation from national electricity transmission networks and supply relatively concentrated settlements with electricity at grid quality level.


Q) Who can use the mini-grid builder?

A) The mini-grid builder was designed to support project developers in sizing and planning of projects. However, it can also be used by financiers and other stakeholders to assess the feasibility of mini-grid projects.


Q) Which support does the mini-grid builder offer to users?

A) The mini-grid builder assists in mini-grid system design, planning and sizing. These steps are essential for the establishment of a successful business case. With the help of the mini-grid builder project developers can size systems based on the effective demand and thus come up with a viable business plan necessary to receive appropriate financing.


Q) Can I use this tool without registration?

A) No. To prevent inappropriate usage, every user has to register first before the tool can be used.


Q) Can I import datasets via an import function?

A) Currently the import of datasets via e.g. an Excel or CSV-file is not possible.


Q) What is the background of the proposed standard data and costs?

A) The proposed data and costs are empirical values based on a mini-grid in Talek, Kenya. These data can be always changed by the user.


Q) Is there a standard survey form that I can use to assess future customers’ ability to pay and load profiles?

A) Yes, the standard questionnaire is attached on the tool. The questionnaire can be downloaded here.


Q) Why do I have to indicate the willingness to pay?

A) These selections are important information to design the best and cost effective mini-grid system. The answers to these questions provide qualitative input to the calculation algorithm.


Q) Is the Willingness to pay used for the calculations of my tariff?

A) No. The willingness to pay is just used to calculate a factor, showing the willingness and making it comparable across many projects.


Q) I don’t have any readings from the appliances to enter in the load profile, what are typical values?

A) Typical values for the appliances can be found in the table below:

Electrical appliances Typical power per appliance in Watt
Light bulbs  8-20 W
Audio  20-60 W
Video  45-120 W
Fan  45-60 W
Fridge  80-150 W
Computers  90-250 W
Mobile phone  2-5 W
Pump/motors  1500-4500 W

Q) How is the ability to pay calculated?

A) The ability to pay of individual customers is entered in absolute values by the user. Then the tool divides the range of ability to pay values from the minimum to the maximum in 5 equal groups. These 5 groups are generated for each category (household, business, anchor client). Now it is calculated how much % (as value from the absolute number of clients in each category) of each category belong to which of these 5 groups. Each group has a weighting. The one with the highest purchase power has the highest weighting – the one with the lowest the lowest weighting. Each category now gets a weighted average ability to pay, from the multiplication of the weighting factor with the percentage. Then the three values of the three categories are averaged, to result in one remaining ability to pay score for this mini-grid.


Q) Is it mandatory to size a hybrid mini-grid always with a diesel generator?

A) No, you can either choose a diesel generator, battery pack or both as back-up.


Q) How does the mini-grid builder calculate the size of the system?

A) The mini-grid builder calculates the size of the system with your keyed-in data and a complex algorithm.


Q) What if a project developer sizes their system using the MGB and goes bankrupt?

A) The mini-grid builder is a tool to assist developers to design mini-grids. It is not an order to invest in the designed systems. The mini-grid builder or the developers of the tool don’t assume any liability for investment decisions carried on the grounds of the mini-grid builder output. Investors are advised to make their own due diligence and independent assessment prior to any investment decision. The tool only facilitates with first level feasibility assessment.


Q) Why is the mini-grid builder limited to a couple of African countries?

A) At this point, the background data is covering five mentioned countries. It is possible to expend the scope of covered countries at a later stage.


Q) What are the given assumptions of the financial factors based on?

A) This assumptions are also values of a pilot project in Talek, Kenya. You can get data for the financial investment factors from someone who has knowledge of the market. You can get investment cost from someone with knowledge of the costs of equipment.


Q) What does ABC tariff mean?

A) ABC is an acronym and stands for Anchor, Business and other Customers.