BENGALURU: Solar Corporation of India ( SECI ) is set to launch its second hybrid tender – for projects combining wind and solar energy – in May. It has issued an advertisement alerting developers that it will be inviting sealed bids for “1000 MW of wind power projects in existing solar power projects” as well as “1000 MW of solar power projects in shadow free areas of wind power projects”, the details of which will be available on a particular website from May 14.This is much larger than the first tender for 160 MW issued by SECI in January this year, which envisaged setting up a Greenfield hybrid project in Anantapur district of Andhra Pradesh . The results of this bid, which also included a small storage component, has yet to be announced.Hybrid power projects have several advantages over standalone ones, especially saving on land and transmission cost. Solar projects in particular need large swathes of land with a single megawatt of capacity requiring five to seven acres – so if some solar modules can be installed in the spaces between wind turbines, the saving on land costs can be considerable. So too, for the developer, a hybrid project needs installing and maintaining one transmission line instead of two had the solar and wind projects been separate. This reduces costs, and also leads to greater continuity of power supply – since both solar and wind power are ‘infirm’ sources of energy, varying according to the intensity of radiation or the speed of the wind blowing. This in turn improves the plant load factor for the entire project.SECI is hopeful that the saving of costs and increased efficiency of hybrid projects will in turn lead to lowered tariffs. Both solar and wind tariffs fell steeply in the last three years, with solar touching a record Rs 2.44 per unit at an auction held in May 2017, and wind dropping to Rs 2.43 per unit at an auction in last December. Since then, however, both tariffs have been rising in subsequent auctions.Only one commercial hybrid project has been commissioned so far, though there have been a few other pilot ones. In mid-April, Hero Future Energies added a 28.8 MW solar plant to its existing 50 MW wind plant in Raichur, Karnataka . This is mainly because no government guidelines relating to tariff and more on hybrid projects have yet been issued so far, and state discoms consequently are not able to buy power from such projects. The Hero project is a group captive one, supplying power to private buyers at a privately decided tariff. Draft guidelines related to hybrid projects were indeed circulated by the ministry of new and renewable energy (MNRE) in September 2016, but no final ones have been issued.There is, however, a natural impediment to setting up hybrid projects. While solar radiation is available in plenty across the country, high wind speeds capable of generating power are only found in select areas of eight Indian states – Rajasthan, Gujarat, Maharashtra, Madhya Pradesh and the four southern states (barring Kerala). Large areas with both high wind speeds and high solar radiation are not that many or easy to find.