Proposal for a solar energy plant

Human global energy use is 18 terawatts per year. That is 18 trillion watts. This looks like a huge amount of energy till you compare it to the amount of solar energy that is received by the earth every year, which is 173,000 terawatts. Clearly, we get more than enough energy to power all our drives.

Solar energy is not new in Auroville. Off-grid communities in the Green Belt have used solar panels for many years. Solar power received a big boost between 1997 and 2000, when a government scheme gave more than 80% subsidy for solar pumps. Many of the solar panels you see in Green Belt houses were bought during this period.

The second big spike in solar power usage in Auroville came during the 2011-13 power crisis in Tamil Nadu, when Aurovilians often had electricity for just four or five hours a day. Solar power was quite expensive in those days, but many residents saw the advantage of self-sufficiency. And then there was Cyclone Thane, which disrupted the power supply from the grid for 21 days while those with solar panels were not affected. More than 60 kilowatts (kW) of solar power was installed in the two months following the cyclone.

It wasn’t only a series of unfortunate events which led us to use renewable energy. A 2009 draft of the Auroville Energy Vision states:

“In Auroville, energy will be consumed as a means to achieve a higher level of collective consciousness rather than for the fulfillment of personal desires and comforts. Auroville will be a township that consumes energy only from sustainable energy sources. To the extent that Auroville uses energy from non-sustainable sources for the building of the town, surplus sustainable energy shall be produced to compensate for such consumption. A change of consciousness and the transformation of matter are essential to achieve ultimate integral sustainability.”

Aurovilians have always been deeply connected with renewable energy, especially solar power. We currently generate about 150 kW of solar power from the rooftops of individual residential buildings, mostly in the Green Belt. These solar systems are not interconnected. In recent years, the focus has shifted to grid-connected solar power systems set up on the rooftops of large buildings, such as the Town Hall, SAIIER and Maroma.

The advantage of these grid-connected systems is that they share the load. So, if SAIIER generates surplus power, it is fed back into the Auroville grid and another building, which has a deficient power, can use this surplus. The installed capacity of grid-connected rooftop solar is already 150 kW. An additional capacity of about 350 kW can be installed on unused rooftops of large buildings, such as Bharat Nivas and Visitors Centre. Also, rooftop solar is an intrinsic part of most new housing projects, such as Sun Ship and Kalpana.

The entire Town Hall and Matrimandir area is now connected to the Auroville grid, which is an internal, Auroville-owned system, designed to make our electricity generation and distribution independent of the unreliable state system. This grid will expand till it covers all of the Master Plan area. An underground high-tension (HT) distribution ring will encircle the Auroville grid.

Moving to renewable energy

Moving to renewable energy, however, is not just a matter of setting up solar panels or windmills. Before we set up the infrastructure, we must look at our needs, think of ways in which we can conserve energy and identify the kinds of appliances that will use minimal energy.

Some of the criticism around Varuna’s in-kind supply of electricity, with residents not paying for their energy consumption, is that it does not encourage consumers to take a hard look at these three aspects. Because electricity is “free,” it is possible that consumers will not use energy in a conscious way. Also, paying for energy might generate financial resources for setting up our energy infrastructure.

Is wasteful use of energy a problem in Auroville? Varuna’s data shows that growth in energy consumption has slowed down after the introduction of “free” electricity. However, it is hard to tell from just one bar graph if Aurovilians are more conscious users of energy now. Growth in consumption can be affected by many factors, including population growth, so we might need to look at that set of data in more detail. Ultimately, how much energy we consume has as much to do with our values as it has to do with availability and cost.

Varuna’s proposal

Varuna’s proposal for a solar power plant is one piece of the larger energy puzzle. Varuna has a plan to produce large amounts of solar energy, initially using on-ground solar panels. The panels will be set up in phases, with the first phase rated at 50 kilowatts (kW). The complete project will generate 560 kW of power.

The problem with on-ground systems is that there can be no trees to cast shadows on the solar panels. The original location of the project was thickly forested and the Forest Group, understandably, objected to cutting the trees. The Forest Group came back with two alternative locations – the Gaia Frisbee field and the Adventure sports ground.

Neither of these alternatives worked for Varuna, especially because these sites are not in the industrial sector, where The Mother had indicated that Auroville’s power would be generated. Varuna has proposed a new location in the industrial sector, which minimizes the impact on mature trees.

Location of the proposed solar power plant in the industrial sector

Straddling the Crown Road, the proposed location works well because it is close to the HT distribution ring, which is planned to follow the Crown Road. One of the most interesting points in Michael Bonke’s presentation during the GM was the fact that the solar plant is being planned exactly where one of the Lines of Force is meant to be built. This means that the solar panels will be moved to the rooftop of the Line of Force when the building is completed. In effect, this is a rooftop solar plant waiting for the roof to be built.

There is one question that did not come up in the GM: when the Line of Force is under construction, what will happen to the solar panels? Such a building is likely to take a few years to construct. So, the panels will have to be decommissioned or will have to be moved to a different location. Which means we will either lose a lot of power generation or we will have to find a large tract of barren land.

The biggest problem with solar power is that the sun does not always shine. So, Varuna’s plan does not end with power generation, but extends to storage as well. The plan is to build a set of interconnected lakes at different altitudes [see AVToday February 2012 # 271]. During the day, solar power would pump water from the lower lakes to one or more higher lakes. At night, the water would flow down from the higher lakes through turbines, generating electricity.

Although this might sound far-fetched, pumped-storage hydroelectricity, as it is technically called, is quite common. In fact, this method of power storage makes up 97% of all grid-level storage in the United States. Some of these pumped-storage facilities are massive, generating thousands of megawatts of electricity. This is a tried and tested technology.

In the Auroville context, the only question is the location and size of the lakes. Some of the lakes might have to be located outside the Master Plan area to get larger spaces and to give more height difference between the higher and lower lakes. The proposed Matrimandir lake may be a part of this interconnected system of lakes.

And what about the water that will be needed to fill the lakes? Varuna has an answer to this as well – in addition to rainwater harvesting, the water will come from a desalination plant. Work on the piping for the desalination plant is already going on [see AVToday December 2016, # 329]. Work on the plant itself has not started.

Desalination is somewhat controversial, with the process needing a lot of energy and generating a lot of pollutants. According to Michael Bonke, the plant will run entirely on wind and solar power, and will not use any chemical cleaners. The waste product, highly saturated brine, will be deposited very far into the sea, reducing the impact on coastal ecosystems. Unfortunately, there are no long-term studies of the effect of dumping desalination waste into the sea. So, from an ecological perspective, desalination still has a few questions around it.

Some of the discussions about solar power in Auroville have been around the issue of ground-based systems versus rooftop solar. Large-scale plants that are set up on the ground obviously need large open spaces. Typically, these are set up in areas that are unsuitable for farming or forests. The advantage of ground-based systems is cost – with economies of scale, these large-scale plants are cheaper to set up. The proposed solar plant in the industrial sector is not particularly large, so there is no real cost advantage. Also, with the Varuna panels to be ultimately placed on the roof of a Line of Force, the ground versus rooftop debate is mostly meaningless.

The General Meeting

How effective was the GM? In view of the strong objections from the Forest Group, the GM was called to share the project and site details so that the community is better informed for giving feedback when the site application is published. Unfortunately, there was very little discussion of the site itself, the objections of the Forest Group and the alternative site proposals. In fact, there were only two members of the Forest Group present at the meeting.

The meeting also pointed to a fundamental question about decision making in Auroville. Should important technical decisions be left to a select group of technocrats? Or should every Aurovilian have a say in every decision, no matter how technical or complex? Like most questions in Auroville, the answer is far from clear.