Here are some smart initiatives that are favorable to us and to our surroundings. They regard the potential green areas in your neighborhood, how you can understand and improve the transportation in your city and how you can benefit from the photovoltaic revolution. Other examples will follow in other articles.

Green spaces

An urban green space is defined as open land with natural vegetation, including urban parks, open public spaces, as well as street trees and greenery. A recent review and meta-analysis of 143 studies in 20 countries shows that living near green space is associated with multiple health benefits, including type II diabetes, cardiovascular mortality, diastolic blood pressure, salivary cortisol, heart rate, heart rate variability (HRV), HDL cholesterol, incidence of stroke, hypertension, dyslipidemia, asthma, and coronary heart disease.1 Public spaces with exercise facilities are improving the health of nearby residents. Trees help diminish atmospheric pollutants, lessen the urban heat island effect, and alleviate stress and sleep disturbance by providing a buffer against traffic noise. Studies have also found a correlation between visiting green areas and boosted immune response. There are such widespread benefits that the availability of green space for everyone is becoming a key parameter of urban planning. Europeans are concerned about its distribution and access.2 The best 50 cities in the US can be found on the excellent site Stacker. Minneapolis, which reserves 14.9 percent of city area for parkland, and with 95 percent of residents living within a ten-minute walk of a park, ranked number one, followed by Kansas City with its Paris of the Plains looking to expand its green space. Cincinnati came in third with more than 115,000 acres of protected green space. The Queen City is also highly rated for its recreation, thanks to its vast system of parks and open spaces. For the readers interested in some of the best urban bike paths in the US, see Travel and Leisure.

My brother-in-law helped establish a green tree area in his neighborhood in Fort Worth. Thus I suggest that we could all investigate the green spaces being planned for our neighborhoods and cities.

Improved urban transport

In the United States, cities represent over 70 percent of direct energy use and generate over 75 percent of gross domestic product. How we manage our cities becomes paramount also in facing international economic competition. The danger is that we build outdated cities with continued inefficiencies of the automobile and highway era. Historically many American cities have invested little in urban public transport resulting in long wait times and thus limited use of the service. As a consequence, these cities were flooded with automobiles, which became overloaded with roads, overpasses, and freeways. Los Angeles comes to mind. The travel times for cars have become excessive in many cities relying primarily on the automobile-based system.

The cities with improved urban transport rely on multiple transport modes such as subways, light rails, buses, ferries, taxis, private automobiles, bicycles, and walking. An analysis of these modes allows local and state transport authorities to assess the effectiveness of walking, cycling, motor vehicles, rideshare, public transit, and telework infrastructure. The multidimensional attractiveness and competitiveness of our new urban transport systems can be measured. At a more aggregated level, they can estimate the equity of access, energy efficiency, carbon emissions, and the preservation of green space.

A good example is New York City, with one of the oldest, largest, and most famous public transportation systems on earth, including one of the largest subway systems in the world serving five million persons daily. The city built the world's first mechanically ventilated vehicular tunnel and is home to an extensive bus system in each of the five boroughs. In addition, there are the citywide and Staten Island ferry systems; and numerous yellow taxis and boro taxis throughout the city. Private cars are less used compared to other cities in the rest of the United States.

In San Diego, the MTS Bus systems are launching ambitious initiatives to host a fully zero-emission fleet of buses by the year 2040. The plan is expected to reduce the carbon emissions from buses by over 40%, improving the local environment and putting the city closer to an optimized urban design. The city is also served by the San Diego Trolley within the metropolitan area and Coaster, a forty-one-mile commuter rail line connecting North County to central San Diego.

Phoenix has built an innovative transport system, allowing sales tax to increase slightly. Already implementing a 20-mile light-rail line in 2008, the new $31 billion transit plan over 35 years (approved in 2015) will go about half to bus service, a third to a 42-mile light rail system, and seven percent to street improvements. The city has implemented several collective choice arrangements, such as van pooling and dial-A-ride, and a program Friends of Transit, to educate the community of the benefits of a well-designed and accessible mass transit system.3

“Montréal is at the forefront of groundbreaking discoveries, home to some of the world’s leaders in Artificial Intelligence, aerospace, education, neuroscience and tech. Add to that list sustainable mobility and intelligent transportation – a sector for which Montréal is pulling ahead of the pack and taking the lead. Living up to the city’s 2017 title as an Intelligent Community of the Year, Montréal’s plan for transitioning to renewable energy includes collaboration between the Smart City Office and the Jalon MTL Intelligent Transportation Institute, working together to transform urban mobility, parking, and dynamic traffic mapping in the city. By 2020, Montréal's greenhouse gas emissions will have reduced by 30% (compared to 1990 levels), putting the city in first place in North America for electric transportation and sustainable mobility.”4 My suggestion is to take a brief vacation (a weekend) in one of these exemplary cities and then begin to relate it to your situation. How do the plans for your city compare?

The photovoltaic revolution

Since the 1973 tripling of oil prices, researchers and energy companies have been working on an alternative source, using solar energy and converting it to electricity with photovoltaic cells. The progress made in reducing the cost of the cells has been in the order of ten-fold over the decades. Even from the beginning of 2016, with a cost per peak watt of 63 cents, the cost has continued to decline to 19 cents in the third quarter of 2020.5 We have reached the point where the high-tech part, the photovoltaic cell, has become about thirty percent of the total system costs. This has resulted in a boom in photovoltaic applications: the most important being that of utility companies producing power for the grid, followed by rooftop systems.

Utility-scale solar has been generating reliable, clean energy for two decades in the US. The energy generated has gone from 1.2 billion kilowatt-hours in 2010 to 90.9 billion kilowatt-hours in 2020.6 There are more than 5,000 major solar projects currently in the SEIA database with 73 GWdc of major solar projects currently operating and 69 GWdc of large-scale solar projects either under construction or under development.7 Solar accounted for 54% of all new electricity-generating capacity added in the US in the first three quarters of 2021.

A recent study finds that with “aggressive cost reductions, supportive policies, and large-scale electrification, solar could account for as much as 40% of the nation’s electricity supply by 2035 and 45% by 2050.” Even in the business-as-usual scenario, “installed solar capacity increases by nearly a factor of 7 by 2050, and grid emissions decline by 45% by 2035 and 61% by 2050, relative to 2005 levels.”8 This implies that even without a concerted policy effort, the technology and market forces will drive a significant switch from fossil fuel to solar energy in electricity generation.

It means that you, as an individual, will have the opportunity to invest in the photovoltaic revolution. One of the most direct ways is to purchase shares or bonds of the utility companies investing in photovoltaics. For example, the US company installing the most photovoltaic capacity in recent years has been NextEra Energy. For the utility sector taken as a whole, the one-year return on the S&P500 utility index was 14.9 percent. Analysts see the sector as low risk and are forecasting continued growth of 5-7 percent with average dividends of 3 percent.

According to recent research, the potential for US rooftop photovoltaics is also enormous: 4.2 TWh, five percent more than the present generation of electricity by the grid, according to recent research.9 Most scenarios hypothesize rooftop installations by 2050 at much less, typically one-fifth that amount. The cost of rooftop solar also has dropped significantly. A decade ago, an average 6-kilowatt hour residential solar system could cost more than $50,000. Now, the outright cost of a typical home installation ranges from $16,200 to $21,400 dollars.10 The practical steps for investigating the possibility of a rooftop system for your home are well known:

  1. determine the ideal size of the solar system and battery for your house, with the help of a supplier;
  2. ask for the estimated costs of the system, here at least two suppliers should assist you;
  3. check on your potential economic savings;
  4. learn about solar incentives and possibilities of financing the initiative.

Now you are in the position to decide to invest (or not) with one or more offers. Average payback times are presently six to nine years. Naturally, this depends on your sunlight exposure, price of electricity, cost of the solar system, local rebates and incentives, and energy use in your home. Indeed, it pays to have an energy-efficient home coupled with a photovoltaic system. Your household appliances and lighting are critical, and they should be in the best performing classes.11 It is smart to have an energy audit of your home before the photovoltaic installation. When designed as an integrated system, rooftop solar and energy efficiency enhances occupant comfort and health, with lower monthly utility bills.

Christmas invites us to become children again. It reminds us as kids; we first learn to destroy and then to build. Breaking everything is easier and faster, but laying brick by brick, bringing our ideas to life is more enriching.


1 Twohig-Bennett, C., Jones A. (2018), The health benefits of the great outdoors: A systematic review and meta-analysis of greenspace exposure and health outcomes, Environmental Research, Volume 166, Pages 628-637.
2 O’Sullivan, F., (2021), Europe’s Greenest Cities Might Not Be the Ones You Think, Bloomberg City Lab, November 17, 2021.
3 Wikipedia, (2021), Public transport in Phoenix.
4 Montreal, (2021), Montréal is a leader in sustainable mobility and intelligent transportation.
5 Statista, (2021), Quarterly prices of solar photovoltaic multi modules in the United States from 1st quarter 2016 to 3rd quarter 2020.
6 Statista, (2021), Solar power net generation in the United States from 2000 to 2020.
7 Solar Energy Industrial Association, (2021), Major Solar Projects List.
8 US Department of Energy, (2021), Solar Futures Study, September.
9 Joshi, S., Mittal, S., Holloway, P. et al. High resolution global spatiotemporal assessment of rooftop solar photovoltaics potential for renewable electricity generation. (2021) Nat Commun 12, 5738 (2021).
10 Sunrun, (2021), Cost of solar in 2021.
11 EESI, (2017), Fact Sheet | Energy Efficiency Standards for Appliances, Lighting and Equipment.