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Dienstag, 2. Mai 2017

‘Look, Ma, No Fuel!’ … Fire-free Cooking with Solar

‘Look, Ma, No Fuel!’ … Fire-free Cooking with Solar

… And no smoke, and no pollution either; no match boxes, no fire-wood collecting, no charcoal burning, and no ash. No waiting for the deliveryman to take away the old LPG cylinder and bring in the new. A cooking revolution looms.
The cooking supply chain is being disrupted. Bounty from the sky, delivered free to the roof, drives the new cooking economy, and not the laboriously drilled, mined, transported, stored, and distributed fuel from the ground, say, kerosene or natural gas, let alone charcoal, firewood or biomass of any kind.
This is a reason to celebrate — for it creates choices for homemakers, frees up women’s time to undertake creative and productive work, and reduces health problems that today affect women and children disproportionately when they cook with smoky systems at home.
Precursors to the impending cooking revolution have been with us for a while — microwave ovens, induction cookers, resistive hotplates, electric water kettles. But they are not strictly fire-free, fuel free, or emissions free in that behind the elegant and useful appliances, in the hinterlands far from cities they are based on electricity produced from burning coal, overwhelmingly, and natural gas lately in the US. Hydro-power or nuclear plants contribute a small portion of today’s electricity, and not without hazards and environmentally high costs.
The revolution I am talking about is local electricity — rooftop solar based, complemented by batteries and related electronics — fed into the house; no electricity grid with giant generation plants and massive transmission and distribution networks necessary.
Wireless “LPG” or “Pipeless” Natural Gas or “Cylinder free Gas”
When I was a student, I remember how on wintry mornings in New Delhi, just outside the campus gate of our engineering institute, sitting in a huddle around a fire, we ordered and sipped tea straight off the boiling pan, holding a small glass with two fingers in a pincer grip. Accompanying the chatter of those around us was the background noise of a hissing kerosene stove. That sound was integral to the scene. Water was always boiling over the flame, tea made in batches, filtered through a cloth sieve, and poured into the glasses, nominally rinsed, I now shudder to think. I am sure paper cups now replace the glasses.
Walking along the streets of Pune, on certain corners one sees vendors of dosas, often outside the gates of colleges. Half the joy is in watching the master street chef prepare them in front of your eyes. Here too, alongside the bustle of the street, and the circle of observers waiting their turn with the food, is the hissing stove under the large flat iron pan, always kerosene-fired. The sound of the stove is again a part of the overall experience.
Consider backyard cooking in U.S. homes. The setup is elaborate, with coal or propane fires and grilles. The ritual of assembling the food to be grilled, and the lighting of the cooking range builds a festive, holiday atmosphere. But can it be simpler, without loss of atmosphere, with solar panels and batteries? I think so.
Indeed, on March 29, in Solana Beach, Calif., Dr. Barry Butler, Cindy Davenport, Roger Davenport, and I cooked toor lentils and stir-fried green and red peppers, onions, ginger and spices on a hotplate fired by solar panels, and ate it over rice in Dr. Butler's backyard.
Cooking Without Burn-ers

Fast-forward a year or two out, and the tea and the dosas will be the same, but cooked without fire, without kerosene, without the hissing noise. How? Solar-powered, battery enabled, over resistive hotplate or induction cookers. A portable solar canopy, a large umbrella over the fire-less stove collecting solar radiation and feeding it to the cookstove, mediated by a Li-ion battery. Personal, portable, ad hoc cooking in the open for the common man — no “burn”er necessary.
In the U.S., Sears, Home Depot, IKEA, Target, Walmart, and perhaps Best Buy, may include solar cooking systems in their stores and catalogs.
Solar Systems Design with Cooking at the Center
Solar Home Systems (SHS) have historically focused on lighting, phone charging, sometimes fans and TVs. And the focus on lighting for un-electrified villages in Africa, India, Bangladesh, Haiti, and elsewhere is as it should be — light after sundown must be among the most critical uses of electricity.
To me, lighting is now a done deal, a solved problem. With solar panels and batteries plus extraordinarily efficient LED bulbs, light is, if I may so describe it, easy. Solar systems may now be designed for the most energy intensive, yet critical, application for a home — cooking. If we do so, applications like lighting and charging for phones, laptops, TVs and home electronics will come with cooking at incremental cost, as a byproduct.
At What Cost?
The prices of this next generation cooking system will represent amortized capital costs, and not the costs for fuel and the logistics infrastructure as today. The capital first costs are high for rural villagers in emerging economies, but if those costs are translated into monthly payments, paid using phones, as the villagers do today, they are reasonable and affordable, and over time cheaper than for LPG.
For instance, the monthly costs of a solar cooking solution costing, say, $1,200, with an up to 20-year life for solar panels, less for batteries, and with ~ 9 percent cost of money, would be close to Rs. 740/month, the same as that for a LPG cylinder without subsidy in India. This is about $11/month, or $0.37/day, or Rs. 25/day for a family of four. The poorest rural households worldwide pay more than this for kerosene burning today. The only “solution” cheaper would be the “free” cooking by collecting firewood and burning it in a cookstove, however crude or well-designed.
This solar-based cooking solution is not merely for rural households without electricity, or street vendors, or backyard cooking in the U.S. Even in apartment homes in urban areas, the solution can be deployed to deliver an even lower cost solution with suitable optimization.
A broader question arises: What is the hub of a microgrid design of the future? Substation? Supermarket? Municipality? Neighborhood? Home Owners Association? At least one hub might be a solution with cooking as the core application in a cluster of apartment buildings.
Images courtesy of Mahesh Bhave.
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