# The world's fully solar-powered airport

Discussion in 'Architecture & Engineering' started by Plazma Inferno!, Mar 16, 2016.

1. ### Plazma Inferno!Ding Ding Ding DingAdministrator

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Fed up with their hefty electricity bill, managers at Cochin International Airport in southern India took matters into their own hands. Three years ago, they began adding solar panels -- first on the roof of the arrivals terminal, then on and around an aircraft hangar. The success of those initial efforts led to a much bigger endeavor and eventually, independency of the electricity utility grid.
Last year, the airport commissioned the German company Bosch to build a vast 45-acre solar plant on unused land near the international cargo terminal. The plant came online in August, making Cochin the world's first fully solar-powered airport. The tens of thousands of panels generate on average slightly more than the roughly 48,000-50,000 kilowatts of power that the airport -- the seventh busiest in India -- uses per day. Surplus energy is fed into the wider electricity grid.
The big project cost around 620 million rupees ($9.3 million), a sum the airport expects to save in less than six years by not having to pay electricity bills anymore. It also estimates the solar plant will avoid more than 300,000 metric tons of carbon emissions from coal power over the next 25 years. http://money.cnn.com/2016/03/14/technology/india-cochin-solar-powered-airport/index.html?ii ajanta likes this. 2. ### Google AdSenseGuest Advertisement to hide all adverts. 3. ### JeevesValued Senior Member Messages: 2,866 There are also projects underway at a couple of US airports, at least one in Africa and one in Canada - that I know of. Probably lots more. There are clever people beavering away at green technology. I do wish it had come 50 years sooner. 4. ### Google AdSenseGuest Advertisement to hide all adverts. 5. ### billvonValued Senior Member Messages: 15,445 I tend to doubt that. I could believe that it would be a net-zero use facility, but I bet they still use conventional power sources at night. 6. ### Google AdSenseGuest Advertisement to hide all adverts. 7. ### JeevesValued Senior Member Messages: 2,866 Why should they? We don't. Not only does airport activity decrease - if not cease altogether - at night for safety reasons, but they have plenty of space for batteries - which are improving all the time. There is a considerable saving in the use of local energy: no wires and poles to maintain, repair and replace, plus the 5 or 6% of power lost in transit and no unexpected outages due to storm damage, equipment failure, negligence or incompetence on the part of the supplier. Last edited: Mar 16, 2016 8. ### billvonValued Senior Member Messages: 15,445 Let's run the numbers! I will first assume the airport uses about as much as our airport (Lindbergh Field.) It is one of the smallest international airports in the US, exists in a very moderate climate (i.e. low A/C and heat use) and has spent millions on efficiency improvements (LED lighting, efficient A/C etc.) It uses 145 megawatt-hours a day. To plan for 5 day autonomy, which is industry-standard, that means you need 726 megawatt-hours of storage. Using Surrette batteries (optimized for very large systems) and planning for 50% discharge you'd be looking at 500,000 batteries, weighing a total of 60 million pounds, at a cost of$181 million.

Now let's use their numbers. If they are using 50 kilowatts average (very low for an airport with a control tower, but let's go with that) then they are using 1.2 megawatt-hours a day. That translates to 4000 batteries at a cost of $1.5 million (replaced every 5-10 years) and a weight of 500,000 pounds. You think that will all equate to a savings of$15 million over an airport with a 50 year life? Also keep in mind that:
1) Large battery based systems are generally less reliable than grid power
2) Unless your recycling program is perfect, half a million pounds of lead every 5-10 years is something of an ecological nightmare
3) You'll have to replace those 4000 batteries once every 5-10 years.

9. ### JeevesValued Senior Member

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I have no idea what their grid charges are.
In India? Are you sure? What's their main source - water? That could become a problem in the very near future. It could in many places. Nuclear has its drawbacks and there is plenty of controversy over the big wind turbines. The next 50 years of grid is far from assured - nor do we know where its price will go. You can budget for your own projected costs, not for those of a volatile industry over which you have no control.
I understand India is where the US sends its reclaimable electronic waste, for the little girls to salvage. I guess, if anybody has a good recycling system, it would be them.
We've had some of our batteries for nearly 15. The more recent installation, when we expanded the system to the whole house, was four years ago - a better class of battery, all second-hand (less than half the price of new), with a 5-year warranty. The new industrial deep cycle ones are rated 10-20+ years useful life.

Whether it's cost-effective in any specific application depends on local conditions and electricity use.
The householders I know who are off-grid did it either for the independence or because their geography made hydro installation prohibitively expensive.

10. ### billvonValued Senior Member

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Mostly coal currently.
You give up control to the power company or you give up control to the battery company - you're still not autonomous.
They recycle a lot; about 70% of their batteries are recycled. However, their program is far from good.
==========
Problems of lead and human health in India
Dr. Subhojit DeyAssociate Professor, Indian Institute of Public Health, (IIPHD)
June 5 2015

Economic Times

. . .
Another major source [of environmental lead] is lead acid batteries, a familiar consumer product and commercial tool with applicability in automobile sector, solar arrays, backup power via “inverters” and so on. 70 % of lead in India is recycled as secondary/Used Lead Acid Batteries (ULAB), and more than half of this recycling happens in unregulated, informal sector using improper methods of smelting with scant knowledge nor regard for health, safety precautions or population control. The inhalation of lead fumes and ingestion of lead dust from these backyard operations are posing serious threats to the human health in the densely populated urban centres and towns where they are mostly located.[/quote]
That's great. Industry-wide, flooded batteries that are cycled daily generally see a 5-10 year life. Completely off-grid systems can make economic sense when there is no other choice (i.e. no utility access within 10 miles) but almost never make sense when any grid power is available. Solar + battery is generally more expensive than on-site generation from fossil fuels, so that's what most people go to first (if their primary issue is cost or reliability.)

ajanta likes this.
11. ### JeevesValued Senior Member

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There are various points of view, not all strictly economic, and I certainly can't read other people's minds.
One issue is that commercial hydro, which has been reliable in the past may not continue so in the future. There is no hard information on how high the price will go - only that it will rise. We've stayed connected, because we're getting old and don't know how long we can stay out here. We use maybe $3 of hydro a month, and pay$43 for 'delivery', taxes and 'debt retirement' (Which is really cute, since the present owners bought Hydro from the government, i.e. us, and we didn't get a penny.)
We also don't know what technological advances will be made in alternative energy - can be fairly sure they'll come, thick and fast, once there is a demand. We don't know what environmental, operational and political challenges each kind of power generating will face in the future. We know coal isn't very good and we know wires, poles and substations aren't the most efficient mode of delivery.
It seems to me, whoever is experimenting with innovation will add to our knowledge, whether their experiment is a success or a failure.

12. ### billvonValued Senior Member

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Perhaps. I'd expect some places to get less rain and some to get more - which would indicate that the patterns of use will change, but not necessarily the amount.

In addition, hydro is rapidly throttleable, and can be used to store unused energy in the form of captive water. Thus hydro plants become excellent peakers, and complement solar and wind very well. i.e. allow shutdown of the hydro plant (and storage of its energy) when wind/solar are producing.
That's where power prices are heading - generation charges and separate delivery charges. Since solar users often use zero kwhr a month (average) and get something like a \$5 bill, as time goes on they either have to raise the rates on everyone else or start charging a fixed per-month amount for delivery/overhead.
Well, there's been a demand for about 150 years now.
Definitely.