Urban sprawl is an unavoidable consequence of population growth, especially in poor, urban areas in developing countries. In 1789, Reverend Thomas Malthus predicted that the human population would grow until the point of mass starvation. Malthus has not been correct in his prediction, but one can’t help but ask, are we moving in that direction? Better yet, what can we do to ease the strain of accelerated population growth?

The growth rate of the human population rose about 1.5% each year through the 1950s and hit a high of 2% in the early 1960s. It is believed that the repaid growth seen in the 1960s was the result of better preventative medicine, vaccines, and healthcare. The present human growth rate is roughly 1.1% per year, with a forecasted slowdown to .5% by 2050. Even with the predicted slow down in growth, there will still be a strain on resources and an increase in waste and pollution.

Perhaps even more alarming is the predicted change in population that is expected to occur between today and 2044. The world population is presently around 7 billion; in the next 29 years, the population is expected to increase to 9 billion. Natural resources, many of which cannot be replaced or recycled, will be depleted. It is no wonder why scientists, engineers, and lawmakers are looking for alternatives to our traditional energy sources.

In response to concerns over resource depletion, scientists and engineers have been developing creative ways to incorporate solar and other renewables into urban landscapes. These energy solutions allow for attractive but useful ways to use the limited space available in large cities. Examples of these solutions include solar rail stations and highways. A certain city has even drafted legislation requiring new buildings to incorporate solar or greenery into their rooftops.

A thorough internet search failed to yield any results confirming that solar roads presently exist; however, there is plenty of information about ambitious companies creating and testing solar cells that can withstand the wear and tear of constant vehicular travel. With grants and funding from the Department of Transportation, a handful of companies are trying their hand at developing heavy-duty cells. Some of the challenges of creating these solar roadways include traction, vehicle weight, and weather conditions. It is unclear when, and if, solar roadways will become a reality.

Densely populated cities with limited space and/or resources can benefit from the incorporation of solar into their public transit, especially if there are frequent power outages. Some train stations in India are jumping on the solar bandwagon. Notably, a station in Manwal on the Jammu-Udhampur rail route incorporated solar partly because of frequent power outages. The solar panels are intended to supply power in emergencies or during outages.

If solar roadways and rail stations aren’t enough, a city in France has required that new buildings in commercial zones be built with “green” rooftops containing either solar or plant greenery. It is estimated that all rooftops in France represent 70% of the solar capacity of the country. On rooftops, solar panels can serve dual purposes. One of those purposes is keeping the building underneath cool from the sunrays; the other purpose is to absorb the sunlight and generate electricity. It is no doubt that the use of the panels will decrease the host building’s dependency on the grid.

Though this article contains a solar overtone, it is important to mention that wind and geothermals are also being incorporated into the urban landscape. Regardless of what renewable product is being used, it is important to note that they each play their part in reducing consumer and commercial dependency on traditional power sources. In turn, as resources become scarce, these new power sources can ease the depletion of resources and reduce pollution.

For more information about population statistics, please visit the US Census Bureau Website

For more information about solar roadways, please visit: http://www.greentechmedia.com/articles/read/Department-of-Transportation-Official-Discusses-Solar-Roadwa

For more information about solar/greenery laws in France, visit: http://www.cbsnews.com/news/france-passes-new-law-to-cover-rooftops-with-plants-or-solar-panel/