YouSolar is a Santa Clara startup with a heavy duty solar/DC-based nanogrid system called PowerBloc for large/luxury residential or light commercial applications.

To clip from their site:

Say Hello to the PowerBloc. The YouSolar PowerBloc® is a solar nanogrid that delivers reliable and clean power with little or no dependence on utility power. The PowerBloc uses a unique modular power architecture. The PowerBloc can meet the needs of a home or scale to power a business.

A New Day for Solar. The PowerBloc captures the sun’s energy with YouSolar’s proprietary STEP™ DC-DC micro-converter. STEP maximizes solar production from each panel, giving you more clean solar energy. Our micro-converter solves even the most complex design challenges, and it is more efficient and safer than any other solar array technology. Installers love STEP because it is simple to install.
Power a Modern Life. The PowerBloc delivers the high power necessary to run a whole home or business. It can power air conditioners and other large loads and even charge an electric vehicle. The modern world runs on electricity, and the PowerBloc has you covered.

Choose Your Power. The PowerBloc seamlessly integrates multiple power sources such as solar, utility, or generator power. Control of all sources is seamless with no need to switch between them. PowerBloc has the industry’s most sophisticated energy storage system that delivers all the energy you need.

View Your Power. Control your system with DIYA™. This beautiful and highly intuitive tablet user interface comes with your system and makes understanding and operating the PowerBloc easy and enjoyable. DIYA connects directly to your PowerBloc, so it stays connected even when there is an internet outage. For those who like to see their PowerBloc from anywhere, a web app version of DIYA is coming soon.

Gain Insight and Take Control. Much more than a dashboard, DIYA gives you complete control of your system. YouSolar delivers a satellite-based hourly solar production forecast using our in-house SPOT™ forecasting service. We use satellite terrain radar to let the PowerBloc know when the first and last rays of light hit the solar array.

Experience and Expect More. When in standby mode, DIYA™ is a practical timepiece and weather station, and you’ll find system performance information cleverly integrated into the clock’s dial. Our goals is to turn DIYA into a home automation hub with control over EV charging, your appliances, fire alarms, and home security.

A PowerBloc® Powering a Modern Home in Calistoga, California.
The picture above shows Arnold Leitner, CEO, explaining the PowerBloc® to its owner. The system shown here is a two-cabinet PowerBloc with 10kW of solar, 50kWh of energy storage, and 38 kW of inverter power.
(During the demonstration, the front doors of the PowerBloc were removed. There are no dangerous high electric potentials in the front of the system.)

Here is a PDF copy of YouSolar’s fundraising webpage on Start Engine:

This system very much aligns with the vision I put forth several years ago for a modern DC-powered building nanogrid solution. Check out my conference presentation below: