Burbank’s eSolar Inc. announced on Tuesday it has raised $22 million in additional funding from its existing investors. The money will support the firm’s expansion into the Middle East and North Africa, as well as aid in developing its next-generation of utility-scale solar power plants. The funding round was led by Oak Investment Partners of Norfolk, Conn. and included previous investors, which were undisclosed. Chief Executive John Van Scoter said the funding validates his company’s efforts. “This funding round marks an endorsement of our technology roadmap, and we’re excited to move forward with our partners to pursue projects in the booming (Middle East and North Africa) region,” he said in a prepared statement. The company, founded in 2007, has developed a concentrated solar technology that employs acres of mirrors to capture and focus the sun’s rays, creating a heat source that drives an electricity-producing turbine. It is different from solar panels, which directly convert sunlight into power. In 2009, eSolar built Sierra SunTower, a 5-megawatt project in Lancaster. It also has an agreement with a company in India that is licensed to build utility-scale projects using eSolar’s technology. The company has raised $185 million since it was founded at Pasadena’s Idealab and is backed by large investors, including Google Inc. and General Electric Co.