Challenge
Grid availability
Over the last two decades, evidence shows most developing countries have observed an increase in energy demand largely because of factors such as urbanisation, population growth and improved economic conditions. Nonetheless, the expansion of national energy production and transport continues to lag behind current demand, often resulting in frequent break downs or shortages of the public energy supply. Unfortunately, backlogs in replacement portend likely significant hikes in cost and energy infrastructure. Manddo thus offers a better alternative in terms of independence from the public energy grid and a reliance on fossil fuels.
Fuel price
Fossil energy sources like coal, gas and oil still contribute over 60% to the global energy demand, thus linking energy prices not only to mining- and transportation cost but also to political strategies. As fossil energy sources are limited and the demand grows exponentially, fuel prices will increase markedly on a long term perspective. As long as extraction, transport and processing of crude oil consume less energy than it inherently carries, it is physically reasonable to use it as an energy carrier. Beyond that point, oil will become increasingly useless as an energy source, making it even more important to consider other alternative and sustainable sources such as photovoltaic.
Energy storage
The photovoltaic panels of a solar system convert solar radiation directly into electrical energy, consequently being usable only in the day. In order to dispose of energy at night-time, the solar system requires an energy storage, for which batteries still are the most widespread solution. In contrary to an office building, where the bulk of energy is consumed during the day, a private household requires energy supply at night-time for typical electrical devices like fridge, TV, ceiling fans and light. As a consequence, a photovoltaic system needs to be designed in such a way, that it produces enough energy during daytime, so that the surplus can be stored in batteries for overnight use. Furthermore, a system can be configured to automatically switch over to the public grid or to a diesel generator if the batteries should be empty.
Change of consumption behaviour
The daily electricity production of a photovoltaic system starts at sunrise, reaching its peak at noon, gradually decreasing until sundown, at which time the batteries need to be fully charged to provide energy for the nightime. To avoid an oversized system, it is recommend to use large electrical consumers, like washing machines, preferably at midday when the energy yield is at its peak. Additionally, it is essential to gradually replace electrical devices by low-energy devices.
Upfront investment & payback
Compared to a diesel generator, the upfront investment into a battery-assisted photovoltaic system is noticeably higher. After the installation of a solar system, the monthly cost will drop to almost zero, as the energy from the sun is for free. While diesel generators require permanent fuel refill and have significant maintenance cost, a photovoltaic system runs smoothly for many years with only a minimum of maintenance.
