Smart tech could save billions of liters of water

Mark Kolmar and Michael Szabo, Reuters 22 Jul 09;

LONDON (Reuters) - Americans can save some of the 225 billion gallons of water (852 billion liters) wasted each year through over-watering by installing smart systems which deliver just the right amount of moisture.

Homeowners and companies over-water their grass and plants by between 30 and 300 percent, said Chris Spain, chief sustainability officer at water management company HydroPoint, citing a report by the American Water Works Association.

"The reason for the waste is because of dumb technology," Spain said. "There are 45 million irrigation systems in the U.S. (controlled) by simple timers. They do a great job of keeping time but a lousy job of irrigating to what the land requires."

City landscaping, or "urban irrigation," makes up 58 percent of urban water use, Spain said, adding that the water wasted generates over 544,000 tonnes of greenhouse gases annually.

Smart irrigation systems are programed to optimize water use based on parameters including plant and soil types and amount of sunlight, and also feature weather sensors that monitor soil moisture levels following rainfall.

"U.S. water-related energy use is at least 521 million megawatt hours a year -- equivalent to 13 percent of the nation's electricity consumption," said a River Network Carbon Footprint of Water report published in May.

"The carbon associated with moving, treating and heating water in the U.S. is at least 290 million tonnes a year."

Climate change also affects water levels, with western states experiencing their driest years since records began.

This year marks the third of drought for the most-populous state of California where lawmakers are urging residents to take shorter showers and water lawns less frequently to cut consumption a fifth.

Several studies found that smart irrigation systems command water savings of between 16 and 30 percent over traditional timer-based controllers, which come at a similar cost.

"It's not like solar, lighting or other systems which require vast infrastructure changes," Spain said, adding that his clients have saved $75 million in water cost savings.

Jennifer Riley-Chetwynd of Rain Bird said her company saw a corporate headquarters nearly halve water used for irrigation from 416,000 gallons per year to 214,000 gallons.

Over-watering also pollutes and damages buildings, drawing $375 million in insurance claims in California in 2005, according to the California Insurance Association.

New California legislation makes smart irrigation controllers mandatory for new properties from 2012, Spain added.

BRITAIN

The United States is not alone with concerns over water.

A joint study published on Wednesday by the UK's Energy Saving Trust and the Environment Agency warned that as new homes became more and more energy efficient, hot water use could overtake heating as the main cause of carbon emissions.

"Six percent of the UK's annual carbon emissions are related to water use -- nearly 90 percent of that is from hot water use in the home," the report said.

Britain's Environment, Food and Rural Affairs Select Committee also issued a report on Wednesday to water regulator Ofwat warning that water scarcity will become "an increasingly critical issue in the South and East of England" and urging improved water efficiency

(Editing by William Hardy)

Saving water could cut water-heating emissions by 30%, report finds
Energy Saving Trust and Environment Agency report estimates simple water-saving measures could save a typical household £225 per year
Alok Jha, guardian.co.uk 22 Jul 09;

Britons could save 30% of the carbon emissions associated with heating water at home by following simple advice such as lagging pipes and using low-flow taps, according to energy experts.

They estimate that installing just a few water-saving measures could save a typical household £225 per year on combined water and energy bills.

In a joint report launched today, the Energy Saving Trust (EST) and the Environment Agency examined the carbon impact of domestic water use in the UK. They concluded that heating water would continue to be a major source of carbon emissions from homes in the future unless urgent action was taken to reduce demand and the associated energy losses from inefficient boilers.

Energy use in homes accounts for more than a quarter of the UK's carbon emissions. In a bid to reduce overall emissions by 80% by 2050, the government has announced plans to reduce the footprint of homes by retrofitting existing homes with energy efficiency measures, such as loft and cavity-wall insulation, and wants all new homes built from 2016 to be zero-carbon.

But the energy used to heat water, around 23% of an average home's carbon footprint, will not be tackled by the government's proposals. "If the drive toward zero-carbon homes goes as planned, by the time you get to a really energy-efficient home, the energy required for space heating is going to be quite small, but unless you do something about water use, that's going to dominate and will account for over 70% of carbon emissions," said Magda Styles, water and waste strategy manager at the EST.

But she said very simple methods of water and energy efficiency could take out 5% of the emissions associated with water, equivalent to taking 600,000 cars off the road.

Water-saving technology and sustainibility standards for new homes have helped to reduce wastage but the growing popularity and frequency with which people use power showers means that Britons still use the same amount of water today as they did 10 years ago – around 150 litres per person per day.

"Water is a precious resource and as the government outlined in last week's low carbon transition plan we urgently need to cut carbon emissions to help reduce the impact of future climate change," said Ian Barker, head of water at the Environment Agency.

The EST report suggests taking showers instead of baths, retro-fitting showers and taps with low-flow heads, lagging hot water pipes, washing dishes in a bowl rather than under a running hot tap and installing a water meter. "It's been documented quite well that metering reduces water consumption by up to 15%," she said. "We're not trying to make people endure hardship and do away with hot water. In most cases, it's a simple prevention of waste."

According to the report, changing a 16 litre per minute shower head with a six litre per minute head, and using a 4.5 litre toilet instead of nine litre one, could result in annual savings of 67m3 of water, 371kg CO2 and £225 for an average household.

Getting beyond 30% reductions in CO2 for individual households would be possible, said Styles, by additionally replacing old washing machines and dishwashers with more energy and water-efficient models and more conscious behaviour change that minimised use and heating of water.