KATHMANDU: Nepal with surplus in house energy resources — ironically is facing severe energy crisis. The suppressed electricity energy demand deficit forecast as greater than 90 MW/year is merely an indicator of how deep into trouble we are. Electricity is one of the pillars of development and in the era of rapid global economy, Nepal is falling behind other nations. The trend will continue with current energy crisis. The country needs thousands of MW power plants and at a very quick rate. Large hydro is an option however it requires a longer lead time and large upfront capital. So what might be solution?
There are many solutions to this, nonetheless one is solar roof top PV grid tied system. The system consists of solar panels and an inverter — so smart that it autonomously regulates itself to synchronise with the grid, similar to a power plant. The inverter supplies generate electricity from the PV modules to the local loads and also exports to the grid when in surplus.
Nepal is blessed with solar resource and has huge potential to harness the energy. It has on average more than double the solar insolation (kWh/m2 day) than Germany — the world leader in solar PV installations. In the last five years, the total solar PV installed in Germany has soared from 6 GWp to 32 GWp. Eighty per cent of the installations were rooftop solar systems compared to large solar farms. So what might be the major driver to such situation though favourable policies on both types of installations?
The answer lies in individual investment, individual space allocation and individual operation management of the system. This installation model is far more scalable than the large multi MWp project, where the utility needs to raise huge capital funds, find large space, operate and maintain and build new transmission lines.
In the context of Nepal, a 1kWp grid tied system can be installed within a day by two skilled technicians. Five hundred such skilled technicians can install 250kWp/day and 91 MW/year, that is 91,000 households. Ninety one MW is more or less the annual increase in the national electricity demand. Ideally a 1kWp grid tied system would generate on average five to six units of electricity per day and would cost in a range of 2.5 to 3 lakhs and additional 1to 1.5 lakhs for battery bank to provide around two electric units/ day. The PV modules have 25 years warranty and the inverters have about five years.
The road for solar rooftop grid tied system is certainly not easy — as favourable policy is needed to permit grid connection, to purchase or net meter the surplus power fed into the grid and tax rebate incentives for public encouragement to install PV. Further, the transmission and distribution lines must be updated to support the new generation.
Currently, there are three rooftop grid tied systems in Nepal — 5.5kwp in total. This pilot project is jointly supported by Nepal Electricity Authority and SUPSI Switzerland. The systems are installed at three different locations with different configurations. Two of the system are battery less type and are installed in locations with load-shedding and without load-shedding respectively, while the third has a battery bank and is located in routine load-shedding region. All the three system will be thoroughly monitored for a year. The data is recorded every 10 seconds and the last two months results have been very encouraging. The results from these pilot projects are felt to be essential driver to the policy making and door opening to new market and energy mix.
(Malla is a Programme Officer — Solar Thermal Systems at Alternative Energy Promotion Center/NRREP)
Source : The Himalayan Times