Friday June 14th 2013

WALTHAM, Mass. – June 14, 2013 – EuroSite Power Inc. (OTCQB: EUSP), an On-Site Utility, offering clean electricity, heat, hot water and cooling solutions to hospitality, healthcare, housing and leisure centers in the United Kingdom and Europe, today announced that it has received subscriptions for $4,000,000 aggregate principal amount of Senior Unsecured Convertible Notes from certain accredited investors.

The Notes will mature on June 14, 2015 and will accrue interest at the rate of 4% per annum payable in cash on a semi-annual basis. At the holder’s option, the Notes may be converted into shares of common stock of EuroSite Power Inc. at an initial conversion rate of 1,000 shares of common stock per $1,000 principal amount of the Notes, subject to adjustment. At the scheduled maturity date, each of the holders will have the following options: i) request payment of their principal amount and accrued interest in cash; ii) extend the term of the Notes for an additional 3 years with an automatic decrease in interest rate to 3% per annum; or iii) exchange the Notes for a new non-convertible note with a 3 year maturity and a 6% per annum interest rate; no accrued interest will be lost on such exchange. The Notes are guaranteed on a subordinated basis by American DG Energy Inc., EuroSite Power’s parent.

The proceeds of the offering will be used in connection with the development and installation of current and new energy systems, business development and for general corporate purposes. These Notes and the common stock issuable upon conversion of the Notes have not been registered under the Securities Act of 1933, as amended, or the securities laws of any state and, unless so registered, may not be offered or sold in the United States except pursuant to an applicable exemption from the registration requirements of the Securities Act and applicable state securities laws.

This press release shall not constitute an offer to sell or the solicitation of an offer to buy any of these securities.