What is a Public-Private Partnership (P3)?

You'll find the answer below from the Partnership for Public Facilities and Infrastructure Act Guidelines Task Force which was signed into law by Governor Scott in July 2013. I'll have much more on this interesting document in the near future. Below is an excerpt with highlights from the document:

As local governments around the world are in search of alternative options to finance and deliver projects and infrastructure initiatives, public-private partnerships (P3s) are an increasingly attractive solution. Public-private partnership projects are contractual agreements formed between public and private-sector entities that allow for greater private sector participation in both the delivery and financing of public projects. The transportation sector has historically been the most common industry to utilize P3s, but the use of P3s has expanded into other areas of public infrastructure such as water and wastewater, education, health care, building construction, parks and recreation and technology. 

There are many different P3 models with varying levels of public and private responsibility and financial risk. Public-private partnerships are becoming a common tool to bring together the strengths of both sectors. When executed well, P3 projects benefit both the public and private sectors. In addition to maximizing efficiencies and innovations of private enterprise, P3s can provide much needed capital to finance government projects, thus freeing critical public funds for core services and programs. However, P3 projects do not provide a one-size-fits-all solution to the funding challenges local governments are facing, but are a tool local governments should consider, particularly when faced with budget constraints. 

[and. . .]

With the right parameters in place, Florida is well on its way to being an environment that further fosters public and private entities working together to provide the infrastructure and facility solutions Floridians need.

It is very important in this process to understand what an "unsolicited" proposal is:

• A written proposal for a new or innovative idea that is submitted to an agency on the initiative of the offeror
• For the purpose of obtaining a contract with the government
• Not in response to a request for proposals or any other government initiated solicitation