A solar micro-grid is a type of solar power system that is able to serve multiple customers at the same time. Solar micro-grids can have larger capacities than other solar systems but they cannot supply the same amount of electricity as national grids. They are able to operate independently meaning they can bring electricity to areas where customers do not have the possibility of connecting to the grid. This makes them very useful in remote rural areas and for people who have low-incomes. Bringing ‘clean’ and affordable solar power to these communities has many benefits.
HOW DO SOLAR MICRO-GRIDS WORK?
Solar micro-grids generate electricity from an array of (multiple) solar panels. The solar panels may be arranged in a solar field on the ground or in solar towers. Micro-grids have built in batteries and inverters and power is distributed to customers through traditional power lines. The number of customers served per micro-grid depends on the size of the array and the energy demands of the customers. Solar micro-grids can be easily expanded if the demands of the customers increase by adding more solar panels.
Solar micro-grids can be operated by state utilities, non-governmental organisations (NGOs), private companies or a mixture of these. The owner of the micro-grid is responsible for the maintenance and working of the system and for charging the customers who use the micro-grid.
HOW DO CUSTOMERS PAY FOR POWER FROM A SOLAR MICRO-GRID?
One advantage of micro-grids is that high upfront costs of installing solar systems can be spread throughout a community making them cheaper. They are usually paid for using a ‘fee-for-service’ or ‘pay-as-they-go’ model which means each customer makes regular payments for the power that they use. Often micro-grids include ‘smart meters’ which measure the power used by each customer. Similar to payments made for solar home systems customers can pay the micro-grid owners using microfinance. They often pay using mobile money by exchanging cash for e-money and paying for power using text messages.
Usually the payments for micro-grid power will be a similar or lower price to what customers already pay per month for kerosene for their lamps, disposable batteries and mobile phone charging. More expensive costs for power may be balanced by the advantages of being able to power larger devices. For example, powering a fridge can mean small businesses such as shops can sell cold drinks or fishermen can store their catches meaning they don’t have to sell them straight away. Having access to micro-grid power can increase profits and earnings.
Micro-grids must suit the power needs and size of a community. If customers stop making payments for their power then the micro-grid owner is able to turn off the power to that customer. One problem with this is that if not enough people are using the power then it will become more expensive as the costs become less shared. Usually customers are willing to pay for micro-grid power because they offer larger capacities and can provide ‘alternating current’ (AC) power. Micro-grids can power larger appliances such as fridges, hair dryers and welding machines. If the micro-grid does not provide larger capacities than cheaper systems such as solar home systems then there would be no benefit to choosing this option instead of more affordable options.