Many companies/organizations have Diesel power gensets for power backup. Some of them have solar PV (or some other renewable source like biomass, small wind, small hydro, etc) for power backup. But, why not consider a Solar PV - Diesel Genset Hybrid system?
While most of the companies go for the most common option available - Diesel gensets, they do not consider the long-term operating costs, especially in the face of quickly increasing diesel prices, nowadays. This cost is higher than you think - One detailed study{pdf} (Design of a PV/Diesel Stand Alone Hybrid System for a Remote Community in Palestine; Journal of Asian Scientific Research) in Palastine has established the COE (Cost of Energy) for three different sources, after a detailed experiment -
- Diesel Gensets: $0.774/kWh
- Solar PV (alone): $0.491/kWh
- Solar PV - Diesel Hybrid: $0.326/kWh
Clearly, Solar PV - Diesel Hybrid systems have the cost advantage here. They also have the reliability advantage as one criteria for conducting the above experiment was to achieve 100% availability. The above study had both solar panels and batteries employed as the part of Solar PV - Diesel hybrid system.
With Diesel gensets, the issue not only the rising cost, but also the continuous availability of diesel (especially at remote locations), noise and most importantly CO2/carbon emissions. The Solar PV - Hybrid system can be designed to maximize the utilization of electricity generated by the solar panels and use the diesel gensets only as a backup or for the balance/excess requirement. They have found out that the CO2 emission for the Solar PV - Diesel hybrid system is seven times lower than diesel genset only solution.
Using just solar panels is also a good option (and many companies do this), but there are issues like the cost of energy storage/lack of solar power generation during the nights, etc. Though the above case study included batteries, it is possible to design a Solar PV - Diesel hybrid system without batteries, to achieve further cost reduction. That way, maximum energy from the sun is utilized during the day and the additional requirements (if any) are met using diesel gensets. In places where grid power is available, utilizing that could be given the first priority.
As you can see, this solution has a lot of potential but surprisingly few installations. During the recent TFSC meet at Raintree Hotels, Chennai, a representative from Chemtrols Solar explained how they have successfully implemented a 1 MW Solar PV - Diesel Hybrid solution in a cotton mill at Tiruppur, Tamil Nadu. You can read more details about this from here. PROINSO is another company that promotes Hybrid Diesel - PV systems in India.
Both the above mentioned manufacturers are tied up with SMA for providing Photovoltaic Hybrid Systems. You can read the technical details of the Hybrid PV-Diesel solution from here. Hybrid PV-Diesel systems are (currently) meant for relatively large companies/factories, not for small offices.
Sun's energy is abundant and is available almost everywhere. It is also available at zero additional cost for customers for a period of 25 years (estimated life of solar panels).
Higher initial cost may deter a few companies/organizations from adopting solar energy or solar-diesel hybrid systems for their requirements. But, consider the cost of non-availability of energy and the operational cost of a diesel generator (even for a couple of years). You'll understand why solar PV makes a lot of sense, especially in a country like India.
