20/02/2023
Imagine you are building a home. You decide to go green. So, you google and find an advert screaming, “Full solar kit at Kenya Shillings (Kshs) 30,000 including free delivery in Nairobi.” Having done your research, and taking care of inflation, you set aside a solar budget of 35k.
A few months later, when trying to place an order for your solar, you get a nasty shocker: A well-known solar installing company informs you that a solar system big enough to support your home will cost a minimum of Kshs.300,000 plus labour charge and transport! What changed to increase the cost by 1000 percent? Welcome to the solar world!
When you are shopping for a solar system, it pays to understand what is being offered to avoid frustration. Here is a quick and dirty initiation into the solar world. Subsequent post will give more details and delve into other solutions including backup power systems, physical security systems, and more.
A solar system traps energy from the sun and converts it into a form that can be used in a home. The energy from the sun is either light or heat. So, there are two types of solar systems: Those that convert light into electricity, called PV (Photovoltaic) solar, and those that convert the sun’s heat into, well, heat; these are called solar water heaters (a tank on the roof).
Today let’s talk about PV solar. There are two types of PV solar; small solar systems and big solar systems.
Small solar systems also called solar home systems (SHS). Basically, these are commodities such as TV sets, phone chargers, lighting bulbs, security lights and small refrigerators, that come with solar panels for powering them. They are very handy when you live where there are no utility power suppliers or when you are tired of being harassed by people working for the power company, Kenya Power, for example. The folks who sell SHS like talking about “Full kit”; which, by the way, is not a technical term. A “full kit” consisting of, say, a 20” TV powered by a 60-watt solar panel plus a battery and costing Kshs30,000 can be a good deal.
On the other hand, if you have a fully furnished modern house, and your monthly electricity bill is Kshs2000 or more, you will need a big (3000 to 7000watts) solar system. There are two types of big solar systems. A standalone solar system, also called off-grid system, is for people who want to tell, say, Kenya Power, to go to hell; an off-grid system makes you fully independent of the power grid and its associated agents. The initial cost of this system is relatively high, in the order of Kshs300,000 or more. The other type is called grid-tie system. This is for people who want to reduce their electricity bills but do not, yet, have a full budget to kick out the utility company. Grid-tie systems come with or without batteries. Systems without batteries are pocket friendly and can reduce your electricity bills if you normally use a lot of power during day time. The disadvantage is that they cannot be used during the night. You may, therefore, require a relatively smaller battery, relative to that used in on-grid systems, in order to have power at night in case of a blackouts.
