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There are 23,000 potential sites for Rentricity's hydrokinetic energy recovery systems in the U.S. alone

400 Billion gallons of water run through pipes each day. The moving water has to be slowed down with pressure reduction valves, creating friction and wasting energy

Given the availability of precise measurements for flow rates and pressure, in-pipe hydro is  more predictable than wind or solar energy

Currently, 20 % of water flowing through pipes is lost to leakage. Rentricity's solution offers better leak detection for improved water quality and conservation

RENTRICITY’S renewable energy technology, which captures wasted energy in water pipelines and generates electricity, has potential to offset much of the energy used to circulate water and wastewater in municipal and industrial systems throughout the world.
Innovation Summary

400 billion gallons of water run through pipes each day, half of which is used in energy generation primarily for cooling, a quarter of which is used in agriculture, another 50 billion gallons for personal use, and 50 billion gallons for industrial use. Most of this water is gravity-fed. The moving water gains speed and pressure and has to be slowed down with pressure reduction valves, creating friction and wasting energy.

Rentricity currently deploys two in-pipe hydro energy recovery systems, Flow-to-Wire and Sustainable Energy and Monitoring Systems (SEMS) to convert excess pressure in water pipes into clean electricity. These systems generally include a micro-turbine, generator, sensors, processors, electronic controls, and communications equipment. The electricity produced can either be sold to the electric grid or used behind the meter to offset water systems’ energy requirements, which account for 4 percent of electricity consumption in the U.S. (7 percent globally).

Given the availability of precise measurements for flow rates and pressure within water systems, in-pipe hydro provides a more predictable power supply than other renewables, like wind or solar energy. This consistent in-system electricity generation could provide power for distributed water treatment to increase water quality. It could also power sensors for better leak detection. About 20 percent of water flowing through pipes is lost to leakage, so having a way to detect leaks in more remote sections of water systems could make a significant difference in water conservation.

There are 23,000 potential sites for Rentricity’s hydrokinetic energy recovery systems in the U.S. alone, including industrial and wastewater treatment systems, mandated small dam releases, and water transfer stations, and a significant amount of water infrastructure is currently being built or repaired across the globe. Rentricity envisions a world where all water and wastewater pipes undergo an “energy recovery audit” to identify potential opportunities.


The central idea behind Rentricity’s technologies is to capture energy that’s being wasted and convert it into usable electricity. That, in and of itself, is a dMASS strategy. But Rentricity has greater potential to address multiple problems within a complex system.

First, Rentricity’s systems currently bypass water pressure reduction valves (PRVs). Eventually, the company may develop a “pressure reduction turbine” to both generate electricity and perform the function of a PRV, thereby replacing the need for two separate pieces of equipment. Already, the technologies rely primarily on pre-existing infrastructure. Second, Retricity’s technology provides an energy source closer to the end point of water systems, which could enable more effective, distributed water treatment, as well as power distributed sensors to detect leaks. Finally, Rentricity’s technology comes at an important time. America’s water infrastructure is in disrepair, with hundreds of billions of dollars going towards replacing and upgrading pipes and valves that were put in place up to one hundred years ago. Worldwide, new infrastructure is being built at a rapid pace. Placing an energy harvesting system within these new water systems now will provide a significant source of power and will build resiliency into the systems.


Rentricity was founded in 2003 and has received funding from state energy agencies in Connecticut, New York, and Rhode Island to test and develop its technologies. The company has installed systems in two water treatment plants in the Pittsburgh region and one in Keene, New Hampshire, and another four systems will come on line in 2013.



Resource Fix: A wind turbine for cities

Installation of typical, large wind turbines requires land plus resources to build a tower, which can run upwards of 300 feet tall. Large wind turbines are also often criticized for the noise they can produce.

A new wind turbine design from Poduhvat is a compact design suitable for urban applications. It maximizes wanted benefits (power generation) and minimizes unwanted byproducts (noise). In addition, the turbine can be mounted on existing infrastructure, like lighting poles and building rooftops to reduce the amount of resources needed to build infrastructure for turbines alone. Poduhvat’s design also facilitates the decentralization of electricity production, reducing transmission losses and bringing power closer to where it’s used.

With more than half the world’s population living in cities and urban growth continuing, what are the implications for the way we generate and distribute electricity? What are the opportunities for technologies like Poduhvat’s turbine?



Resource Fix: Using waste heat from servers to keep homes warm

Appliances and electronics generate a lot of waste heat when they operate. As Howard Brown pointed out in a previous post, our homes often become a battleground in an “energy war” between separate appliances, as some pump out heat while others work to cool the air.

On a larger scale, the vast network of data servers that power the cloud accessed by millions worldwide generate an enormous amount of waste heat. These servers are often housed in large quantities in data centers that require massive cooling systems to prevent overheating. The German company AOTERRA aims to change this by distributing servers across networks of homes and using the servers’ waste energy to heat those homes.

By placing servers in homes and connecting them directly to boilers, AOTERRA is taking two separate technologies and attempting to create a system that performs better. It’s an interesting strategy to capture heat that’s not only currently wasted, but has be countered with cooling systems that require even more energy inputs. What do you think of this strategy, particularly in terms of decentralizing the servers? Do you see any downsides that might reduce resource performance? What are some alternatives?