Must have installed the panel in 2005. Since then, they've been 2x to service (about 6 yearly interval). Servicing has been to clean the tubes (get silt and algae inside the tubes that reduces the efficiency) and replace the header tank float valve (it's a standard type of valve). Last time they came in 2016 I paid around RM900.

I haven't done any comparison between electric & solar costs. When we bought the house from the developer, we specified hot water plumbing, that was an additional cost, rather than the cost of individual electric storage tanks offered.

I prefer the convenience of solar, hot water always available in all the bathrooms and kitchen.