Electric pump: lower upfront cost, but you pay electricity bills, risk power outages and higher running cost.

Solar pump: higher upfront, but very low running cost, great for remote/off-grid locations, and strong long-term value if you use a lot of water or rely on the system often. One source notes solar systems are increasingly popular in Kenya due to high solar potential.
When comparing, consider total lifecycle cost (upfront + running + maintenance) and reliability in your location.