It may have started with smart cars and smart homes, but as technology advances, the "smart" trend is taking over entire cities. Across the country and the world, cities of all sizes are transforming their infrastructure, systems, and operations to capitalize on new technologies and integrate connected solutions into the very fabric of how they operate and care for their citizens. Through advances in data collection and analytics, they can anticipate and respond to daily challenges like traffic flow and potential emergencies like severe storms.

But these new smart cities aren't just forward-thinking when it comes to the best ways to serve the public — many of them are also pioneering efforts to incorporate sustainability and energy efficiency into developing smart city solutions. Integration of solar power and other renewable energy sources is quickly becoming a hallmark of smart city planning. Here's a look at some of the innovative ways smart city initiatives and tech leaders are harnessing solar power in their quest to create the cities of the future.

Federal Government Focuses on Smart and Sustainable Development

Last year, the Obama Administration announced a $160 million investment into smart city development. The initiative called for an emphasis on solutions to manage economic growth, crime rates, and — interestingly — climate change.

While sustainability hasn't historically been a top priority in city planning, the current state of the environment is quickly changing that trend. Innovators and tech moguls are focusing on energy efficiency and their environmental impact more than ever before. Smart solution providers are following suit, providing high-tech infrastructure options that can help city governments save on energy costs even as they reduce their carbon output. This is an especially smart pairing because it allows municipalities to consolidate efforts to improve quality of life and sustainability under one umbrella initiative, rather than in multiple separate solutions.

Department of Transportation Makes DC Solar a Partner for Smart City Challenge

Other government departments are pushing smaller initiatives for sustainable smart city development, too. The Smart City Challenge, for instance — a competition instigated by the U.S. Department of Transportation (DOT) — offered up to $40 million to the city that came up with the best "smart city" plan. The challenge encouraged cities to become fully integrated and connected using smart technology and sustainable energy to shape how people and goods get from one place to another.

DC Solar partnered with the U.S. DOT, offering mobile solar generators and electric vehicle chargers worth $1.5 million to winning city Columbus, Ohio. In addition, the company pledged to work with the other six finalist cities to adopt mobile solar technology and incorporate use of electric cars into city infrastructure. DC Solar will also help the cities convert diesel off-grid power generators to solar.

Smart Cities Go Global

It's not just the U.S. that has set its sights on building smarter cities. Across the globe, major cities are moving in the smart city direction. Barcelona has adopted aggressive solutions to incorporate solar energy, electric cars, and sensors, and mobile apps to improve public transportation, security, parking, lighting, and waste management. The city has even made forays into health care solutions by developing a digital community to help counter the problem of elderly isolation.

On a larger scale, Germany has set a goal for the entire country to run on sustainable energy by 2050, which is spurring cities to get smart. Through a combination of private and government-funded projects, German cities are using tech advances to lower energy consumption and bolster renewable energy generation. In addition to maximizing renewable energy sources like wind and solar power, Germany is also focused on electric buses, green construction, smart grids, and rooftop farms.

IBM Predicts Weather Patterns to Maximize Solar Power

The movement toward adopting renewable energy to power smart cities isn't without its hurdles. Solar power is great as long as the sun is shining, but cloudy days can minimize the energy output solar arrays can produce. A single grid-tied home losing solar efficiency isn't a huge problem, but when a city-wide infrastructure is tied to solar power production, being able to plan around periods of low efficiency is critical.

In an effort to mitigate the impact of overcast weather, tech giant IBM is looking at ways to accurately predict cloud cover. As part of the U.S. Department of Energy's SunShot Initiative, IBM has conducted research that they claim produces weather predictions that are 30% more accurate than the National Weather Service.

Increased accuracy will help city governments and utility companies know in advance how much sun a solar plant will receive at any given time, allowing them to better plan their power loads. With proper response, this foresight has the potential to save money and reduce reliance on coal and natural gas power plants that often have to pick up the slack when clouds roll in.

These examples are just the tip of the iceberg when it comes to smart city initiatives. Thanks to solar power efforts and other renewable energy sources, the city of the future is going to be more efficient, more connected, and more sustainable. Making cities smarter and greener will change the way municipalities operate and help citizens maximize their potential as responsible, sustainable members of a global community.