BUILDING INTEGRATED photovoltaic has a much wider application than rooftop solar alone. The government has set up an ambitious target to develop 175 GW renewable energy by 2022, comprising of 100 GW Solar, 60 GW wind and 10 GW biomass and 5 GW small hydro.Of the total 100 GW solar installations,40 GW would be rooftop and balance 60 GWwould be ground-mounted utility scale. The draft NEP (National Electricity Plan) envisages another 1,00,000 MW of renewable energy during 2022-27. Thus,going by the notional share of roof top solar,it will amount
to about 64,000 MW by 2027.
The present roof top installation is clocking around 1,040 MW,and comprises of 283 MW commercial,377 MW industrial, 121 MW government and 260 MW residential.The target set by the government is about 1,500 MW in FY17.The balance 38,500 MW rooftop needs to be installed in the next five-six years, ie, 6,000 MW per year.
Although there is a pressure foracquiring land tract for ground mounted solarplants,the rooftop solarprogramme it seems,is also not accelerating at the expected rate. The woes are being compounded in the form of declaration of firm policy by state electricity commissions with the exception of KERC (Karnataka Electricity Regulatory Commission) leading the pack with its policy declared. The other teething problems remains in the form of net-metering approvals, scientific determination through software modelling, standardisation of installation policy, easy access to finance and a sustainable distribution tariff.
Rooftop installation can be coupledwith BIPV.ABIPVcomprises of a group of solar PV technologies that are built into the host structure, and mayactuallyreplace some building materials (such as windows of roof shingles). BIPV’s potential to seamlessly integrate into the building envelope holds aesthetic appeal for architects, builders, and real estate holders,and this has been one of its principal sources of attraction in its three-decade lifespan.Today,BIPV only claims about 1% share of total PV installations worldwide,but nevertheless the application is picking up very fast.The recently inaugurated SCOPE MINARat Laxmi Nagar,Delhi fora 100 KWp byEnvio EnergyTechnologies Pvt Ltd is a stark testimony.The BIPVhere has a round contour enveloping the crown of the building. This unique project has been able to utilise 8.86 sqm perKwp as against industry average of 10 to 12 sqm per Kwp. Imagine if majority of government buildingswould have resorted to BIPVorthe industry in the form of plant buildings and non-plant buildings within the manufacturing premises (control-room included). The government, then,would have achieved its target rooftop installation in a comfortable zone.The best part of BIPVis that,the same can still be executed even today in existing structures.
There are a few challenges in BIPV execution though.A BIPV module contains less semiconducting material than traditional PV modules, and hence produces a shade lower electricity than a flat panel system of the same size.Further,the sub-optimal angle of irradiation on these non-horizontal surfaces,combinedwith the obstructions posed by surrounding buildings, create diminished returns on increased module deployment.
The BIPVcan have multiplying effect once contoured with flat roofs, pitched roofs, façade and glazing which are very common features for any given building. Given the dwindling availability of land for a ground-mounted PV system, an acceptable irradiation level and a very limited roof top space availability, BIPV emerges the winner.
Incentives have been a common attraction for encouraging BIPVs all over the world in addition to feed-in- tariffs,which have been in force since 2006 in Europe.France offers 0.25 euros/Kwh, Germany 0.05 euros/Kwh, Italy 0.04-0.09 euros/Kwh, UK 6.38 to 13.39p/Kwh,Spain 0.28 euros/Kwh.
It is high time perhaps that the MNRE takes cognizance of the huge potential of BIPV.This can be done byoffering an incentive to give it a formal boost and municipal corporations setting up selectivemandatorymeanstoincludeaBIPV. This opportunity must also be welcomed bythe Indian Green Building Council to include BIPV in their rating methodology.