Smart window developer Soladigm said Monday it has raised a $55 million equity round to bring its energy-saving nanotechnology to market.

The Milpitas, Calif., company is accruing a war chest to mass produce its electrochromic glass, which reduces energy use and costs by limiting the amount of sunlight and heat that enter through windows. Soladigm is planning to open a factory in Mississippi with a $40 million loan from the state and its own private funding. The company originally wanted to start production in the first quarter of this year, but a spokesman said the plan is now to start manufacturing later this year.

Reinet Investments and NanoDimension are the two primary investors in the latest round, and Soladigm believes their involvement — each of the two companies will get a board seat — will help it market its specialty glass in Europe and elsewhere. Reinet, based in Luxembourg, was carved out of luxury goods purveyor, Richemont (which has stakes in firms including Cartier, Piaget, Montblanc) in 2008 to invest in non-luxury goods. NanoDimension’s two offices are in Silicon Valley and Switzerland.

Overall, Soladigm has raised $125 million since its inception in 2007.

Electrochromic windows change colors to reflect or absorb light when a low-voltage electrical current is applied. The ability cools or warms a room and reduces the need to crank up air conditioning or heating. At the same time, the windows shouldn’t become so dark or opaque that they block the view. Soladigm’s technology uses a thin-film deposition process to create conducting layers between two panes of glass for controlling the amount of light and heat that pass through. The layers are conductive oxide films, in between which are an ion storage layer, an electrolyte and an eletrochromic layer.

To control electrochromic windows, people can either can turn on a switch manually or rely on sensors to activate the windows when the room temperature reaches a certain point or during a particular time of the day.

Research on electrochromic glass has existed for several decades, but it’s expensive and that has been a stumbling block for its widespread use. A growing interest in energy conservation and reducing carbon footprint has generated investor interest in electrochromic windows. Minnesota-based Sage Electrochromics also has been building a factory next to its current factory and plans to start shipping the tunable glass in January next year. Saint-Gobain, a major building material supplier in France, first invested and then recently bought Sage.