Here at Gigaom Research I’m working on a ride sharing report that will come out soon. I chose ride sharing as a topic because it’s an area within the share economy that is picking up steam and is emblematic of how smart phones are being used to transform and disrupt an industry—in this case the transportation industry.

To be sure, ride sharing had many obstacles to overcome. There was regulatory opposition from city governments and taxi lobbies. There were social trust issues that require a maturing population of internet users. And there were basic technology challenges that required location based capabilities and seamless payment systems. Finally, for the startups duking it out in the space, there are the invariable concerns about network effects in a market where adequate supply is critical to success.

It seems that many of these obstacles are rapidly being conquered. The traction that ride sharing is getting raised a question in my mind in terms of what may well be the most impactful and positive entry point for investors and entrepreneurs in the cleantech space that want to build businesses that improve resource efficiency.

I caught up with Sunil Paul, the CEO at ride sharing startup Sidecar, whose investors include Lightspeed Venture Partners and Google Ventures. Paul reflected upon where cleantech investing has been and where it might be heading.  Looking back he saw four models of cleantech investing that had come to define the investment space.

1) IT model: Enterprise. The enterprise sales model intrinsic here involves building a valuable asset that businesses are buying based on simple spreadsheet ROI analysis. It often requires a significant sales force to build a customer base. From my perspective, Opower is a classic example of this model.

2) Biotech model. The startups begin with strong IP around an innovation. Typically a partnership will amplify the proprietary advantage by allowing for faster commercialization and the ability to move a product to market.

3) Cash flowing asset model. Familiar to utilities, this model revolves around investments in a core renewable energy asset like solar that then produces a reliable, if modest, cash flow. More efficient capital flows like the strategy being deployed at startups like Mosaic have the potential to innovate this model

4) IT model: Consumer. The key here is to reach a large scale with a differentiated offering that consumers show a preference for. Success stems from increasing volume or exploiting network effects advantages to expand margins. This is the model Sidecar finds itself competing in.

So where does an innovator make a difference if they want to enter the cleantech space? Paul clearly believes that one of the most accessable and exciting options is the consumer IT model where smartphones and IT platforms can be leveraged to create a great user experience that leads to resource efficiency.

Many believe that we’re at the tip of the iceberg for how a smartphone could transform our relationship to transportation, particularly as driver’s license rates decline and millenials show greater loyalty to a smartphone than to an automobile. Imagine an efficient way to make visible all of your public, taxi, ride sharing, car sharing and peer-to-peer car sharing transportation options on one integrated map with built in payment systems. The need for owning a car might be much smaller, particular as a slow trend toward reurbanization of many cities picks up and population density increases.

One of the core background issues framing the conversation about cleantech investing is the reality that creating a tech breakthrough in some of the most critical cleantech sectors like solar power and battery technology is very difficult. At this point those sectors are more defined by economies of scale and efficient commercialization than next generation technology investment.

And the challenge for startups interested in using consumer IT business models to make a difference may well be making the case to traditional cleantech venture firms that a new generation of startups are approaching the cleantech problem from neither a cash flowing asset model nor a proprietary IP biotech model. But rather from a consumer IT perspective.

Going into these conversations, the one thing these startups will always have is the reality that they need much less capital than the other aforementioned models. After all, Sidecar is up and running with just $20 million.