Imagine this:

— A source of clean energy that is is plentiful, free, available on demand, easy to access, and currently virtually untapped
— Wastewater recycling technology that changes a typically energy intensive process into an energy source
— Low cost grid scale storage that supports intermittent renewables, reduces energy price volatility and increases reliability
Luckily we don’t have to imagine them. They are real technologies under development by innovative companies whose CEOs — David Mather of MTPV, Matt Silver of Cambrian Innovation Inc, and Phil Giudice of Ambri — spoke at an E2 New England event on June 16. By the end of the session it was clear that these companies are taking us into a future with vastly improved prospects for lower cost renewable energy, improved use of scarce water resources and drastic energy efficiency.
Using waste heat as a low cost, clean source of electricity
David Mather, CEO of MTPV sees his product as a solution to inefficiencies in electricity generation as well as in industrial energy uses, by utilizing the vast amounts of waste heat created by energy use and turning it directly into electricity. The technology is solid state, scalable, has no moving parts, creates no emissions, and results in 100% green energy. It uses thermo-photo-voltaic cells to capture the photons produced by the sun or other heat source. By placing the thermal capture device, a semiconductor chip, next to the photovoltaic cell and employing a submicron gap between them, the photons are attracted to the PV cell and create energy. This technology is very cost effective, and can increase the efficiency of electricity generation by a multiple of 50! The company received the top award at SEMICON West's Silicon Innovation Forum.   
Creating energy while cleaning wastewater
Mathew Silver, CEO of Cambrian Innovation, described Cambrian’s product, the EcoVolt. It generates clean electricity and clean heat directly from industrial wastewater streams. The high quality, renewable biogas created within the reactor is captured and used as a fuel in a combined heat and power system. A typical installation can create 30 – 200 kW of power. The current aerobic technology for such treatment, mixing water with air in huge pools is very land and energy intensive, consuming some 3% of US electricity. The EcoVolt technology uses electrically active microbes to create clean water, which can be reused, and methane gas, which can be used to generate heat and or electricity. The entire treatment system is delivered prefabricated to the site, and turns a process that would typically consume large amounts of energy into one that actually creates energy. It is much less expensive than traditional waste treatment technologies and offers a high return on investment due to its production of renewable energy. The company won the grand prize in the nationwide Cleantech Open.
Low cost, grid scale storage
Phil Giudice, CEO of Ambri, described the company’s liquid metal battery technology, which can store vast amounts of energy at dramatically lower cost. This technology shows promise for storing the energy produced by intermittent sources like wind and solar for use when they are not producing. This could avoid or defer investment in generation, transmission and distribution infrastructure, and enable the switch to 100% renewable energy.  It improves the reliability of the grid, reduces costs, and allows demand and supply to be separated in time. It can also smooth out the daily peaks and valleys of intermittent source production, reducing the need for hydrological storage and new nuclear power plants as back up to renewables. It is simple and inexpensive to make, uses abundant natural materials, has a fast response rate, and can operate at very high temperatures. It is also flexible, highly efficient, has long life, and is both safe and silent. The Cleantech Group named the company Rising Star of the Year in 2013.
Many thanks to our host, the law firm of Foley Hoag, LLP.