Linear generators to support a net-zero carbon electric grid


Stanford engineers Shannon Miller, Matt Svrcek and Adam Simpson founded Mainspring Energy in 2010 out of the US. Their research into high-efficiency methods of converting fuel to electricity led to the development of a clean on-site power generation technology that enables affordable and reliable electricity while providing flexibility to the grid.


Series E

Focus sectors







Investment rationale
Despite the soaring adoption of renewable power, electricity production still accounts for 23% of global GHG emissions. And while solar and wind power are now often cheaper than fossil fuel alternatives, switching to 100% renewable power comes with two big challenges. First, the wind doesn’t always blow and the sun doesn’t always shine, but we do want reliable electricity 24/7. Secondly, renewable power is produced in different locations (think rooftop solar or offshore wind) than fossil fuel power, meaning our current grid is not optimized for these new flows. As such, we need technologies to balance the grid and provide alternatives when needed, including those that can provide stable power when the grid is able to provide so.
Mainspring Energy has developed a modular power generator that produces clean power on-site. The generator mixes air and fuel which are compressed until a low-temperature reaction occurs, creating stable linear back-and-forth motion of the key components of the generator that move through copper coils which creates electricity. What makes the generator unique is that it can switch between clean fuels like hydrogen, ammonia and biogas, and use software to match power output with demand. It can integrate with onsite solar and energy storage, and being fully dispatchable it can provide power also when the grid is down.
Competitive advantage
Mainspring Energy’s technology delivers not only a unique contribution to help decentralize the energy system, but also flexibility to the grid with a solution that can act alone or complement other decentralized solutions such as solar. Flexibility is key to the renewable electricity transition, and their technology can act as the backbone of any renewable microgrid. As such, the company will help enable the continued rapid adoption of renewables.
Shannon Miller
Matt Svrcek
Jacek Prus
Investment fund


Lightrock is a global impact private equity platform spun-out of the Liechtenstein Global Trust investing across people, planet and productivity.

Invest in the future you wish to see

Carbon Equity logo
Follow us
Impact in your Inbox
Our monthly newsletter on all things climate tech investing
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.

Any information presented on this website does not constitute, and under no circumstances shall this information be deemed or construed to be a prospectus, an offer to sell, or the solicitation of an offer to buy or subscribe for an interest in the feeder funds or fund of funds of Carbon Equity B.V. “Funds”, unless clearly indicated otherwise. No part of this information or the fact that of its distribution should form the basis of, or be relied on in connection with, any contract or commitment or investment decision whatsoever.

The issue and distribution of any information on this website may be subject to statutory or other restrictions in certain jurisdictions. Carbon Equity B.V. requests that individuals taking possession of this information familiarise themselves with and comply with those restrictions. Carbon Equity B.V. rejects liability for any violation of any such restriction by anyone whomsoever, regardless of whether that individual is a potential investor. This website in itself does not entail any offer of any security or an invitation to make an offer to purchase any security to any individual in any jurisdiction where such is not permitted according to the applicable law and regulations.

The Funds of Carbon Equity B.V. will only be offered to potential investors at a later stage pursuant to fund documentation to be prepared and distributed by Carbon Equity B.V., through a dedicated account environment and clearly indicated as such. Any person should note that the Carbon Equity B.V. Funds will eventually exclusively be offered by Carbon Equity B.V. to potential investors in permitted jurisdictions who commit to an initial investment of at least EUR 100,000 or fall under other applicable exemptions. Carbon Equity B.V. will act as the Alternative Investment Fund Manager (AIFM) of the Funds and will benefit from the Dutch sub-threshold regime, pursuant to article 2:66a of the Dutch Financial Supervision Act (Wet op het financieel toezicht).

As such, the Carbon Equity B.V. will benefit from an exemption from the license requirement and ongoing requirements of the AIFMD. Moreover, no prospectus requirement applies in light of article 1(4)(d) of the Prospectus Regulation. Any Funds and Carbon Equity B.V. will therefore fall outside the scope of supervision of the Netherlands Authority for the Financial Markets (Autoriteit Financiële Markten, AFM) and the Dutch Central Bank (De Nederlandsche Bank, DNB)

Carbon Equity does not make investment recommendations and no communication, through this website or in any other medium should be construed as a recommendation for any security offered on or off this investment platform. Alternative investments in private placements, and private equity investments via feeder funds in particular, are speculative and involve a high degree of risk and those investors who cannot afford to lose their entire investment should not invest. Prospective investors should carefully consider the risk warnings and disclosures for the respective fund or investment vehicle set out therein. The value of an investment may go down as well as up and investors may not get back their money originally invested. Past performance is not necessarily a guide to future performance. An investment in a fund or investment vehicle is not the same as a deposit with a banking institution. Please refer to the respective fund documentation for details about potential risks, charges and expenses. Additionally, investors will typically receive illiquid and/or restricted membership interests that may be subject to holding period requirements and/or liquidity concerns. In the most sensible investment strategy for venture capital investing, venture capital should only be a part of your overall investment portfolio. Further, the venture capital portion of your portfolio may include a balanced portfolio of different venture capital funds. Investments in venture capital are highly illiquid and those investors who cannot hold an investment for the long term (at least 10 years) should not invest.