According to Investopediacapital project is a project in which the cost of the product is capitalized or depreciated. The most common examples of capital projects are infrastructure projects such as railways, roads, and dams. In addition, these projects include assets such as subways, pipelines, refineries, power plants, land, and buildings.

Infrastructure is the term for the basic physical systems of a business or nation — transportation, communication, sewage, water and electric systems are all examples of infrastructure. These systems tend to be high-cost investments and are vital to a country’s economic development and prosperity.

The creation of renewable energy assets are infrastructure projects. They are often referred as sustainable infrastructure projects due to their environmental benefits.

Wikipedia provides a good definition. Infrastructure may be owned and managed by governments or by private companies, such as sole public utility or railway companies. 

Generally, most roads, major airports and other ports, water distribution systems, and sewage networks are publicly owned, whereas most energy and telecommunications networks are privatelyowned. 

Publicly owned infrastructure may be paid for from taxes, tolls, or metered user fees, whereas private infrastructure is generally paid for by metered user fees. Major investment projects are generally financed by the issuance of long-term bonds. Government-owned and operated infrastructure may be developed and operated in the private sector or in public-private partnerships, in addition to in the public sector. As of 2008 in the United States for example, public spending on infrastructure has varied between 2.3% and 3.6% of GDP since 1950. Many financial institutions invest in infrastructure.

According to researchers at the Overseas Development Institute, the lack of infrastructure in many developing countries represents one of the most significant limitations to economic growth and achievement of the Millennium Development Goals (MDGs). Infrastructure investments and maintenance can be very expensive, especially in such areas as landlocked, rural and sparsely populated countries in Africa. It has been argued that infrastructure investments contributed to more than half of Africa’s improved growth performance between 1990 and 2005, and increased investment is necessary to maintain growth and tackle poverty. The returns to investment in infrastructure are very significant, with on average thirty to forty percent returns for telecommunications (ICT) investments, over forty percent for electricity generation, and eighty percent for roads.

The source of financing varies significantly across sectors. Some sectors are dominated by government spending, others by overseas development aid (ODA), and yet others by private investors. In California, infrastructure financing districts are established by local governments to pay for physical facilities and services within a specified area by using property tax increases. In order to facilitate investment of the private sector in developing countries’ infrastructure markets, it is necessary to design risk-allocation mechanisms more carefully, given the higher risks of their markets.

The spending money that comes from the government is less than it used to be. Compared to the global GDP percentages, The United States is tied for second-to-last place, with an average percentage of 2.4%. This means that the government spends less money on repairing old infrastructure and or on infrastructure as a whole. 

In Sub-Saharan Africa, governments spend around US$9.4 billion out of a total of US$24.9 billion. In irrigation, governments represent almost all spending. In transport and energy a majority of investment is government spending. In ICT and water supply and sanitation, the private sector represents the majority of capital expenditure. Overall, between them aid, the private sector, and non-OECD financiers exceed government spending. The private sector spending alone equals state capital expenditure, though the majority is focused on ICT infrastructure investments. External financing increased in the 2000s (decade) and in Africa alone external infrastructure investments increased from US$7 billion in 2002 to US$27 billion in 2009. China, in particular, has emerged as an important investor.

According to the infrastructure investor, the top 50 infrastructure investors in 2018 were : 

  1. Macquarie Infrastructure and Real Assets Brookfield Asset Management
  2. Global Infrastructure Partners
  3. KKR 
  4. IFM Investors
  5. Stonepeak Infrastructure Partners
  6. I Squared Capital
  7. Colonial First State Global Asset Management
  8. Ardian
  9. Energy Capital Partners
  10. AMP Capital
  11. BlackRock*
  12. KDB Infrastructure Investments Asset Management Company 
  13. Antin Infrastructure Partners
  14. EQT Partners
  15. ArcLight Capital Partners
  16. DIF
  17. Copenhagen Infrastructure Partners**
  18. Infracapital
  19. Partners Group
  20. Hermes Investment Management
  21. The Carlyle Group
  22. F2i
  23. Blackstone
  24. InfraRed Capital Partners
  25. Actis
  26. LS Power Group
  27. Dalmore Capital
  28. Sunvision Capital
  29. QIC
  30. Greencoat Capital
  31. Ping An Asset Management
  32. Morgan Stanley Infrastructure
  33. Equitix
  34. DWS
  35. Axium Infrastructure
  36. Meridiam Infrastructure
  37. Capital Dynamics
  38. Digital Colony 
  39. Mirova
  40. iCON Infrastructure
  41. Goldman Sachs 
  42. Infrastructure Partners 
  43. Starwood Energy Group***
  44. Equis
  45. China Communications Construction Company 
  46. Aviva Investors
  47. Oaktree Capital Management
  48. Northleaf Capital Partners
  49. Basalt Infrastructure Partners
  50. 3i Group