Clean energy investment dropped 11% last year to $268.7 billion according to Bloomberg New Energy Finance. After years of growth in a variety of industries, this could be the bursting of a bubble in green investments spanning from venture capital to the stock markets.

But the surface numbers don't tell the whole story -- there are some green shoots in the green investment world that investors should be aware of.

Fear takes over One of the logical reasons for the pullback in investments is the performance of green investments since the middle of 2011. The chart below shows just a few of the bigger names in clean energy; they're results only a short seller would love:

data by YCharts

The clean energy business has really been a victim of its own overinvestment in many cases. Wind and solar got billions upon billions of dollars in funding to expand capacity in the late 2000s and the result was overcapacity in both markets that caused prices and profits to tumble.

In biofuels, the quick rise of oil prices in the 2000s led to a lot of hope for advancement, but profits have been fleeting. Take ethanol: When feedstock prices go up so do costs, and eventually the economic viability of biofuels falls apart. Solazyme Inc (NASDAQ:SZYM) , which may have the best chance to survive, has signed a number of partnerships to expand both energy and non-energy production, but revenue is declining and losses are growing.

Wind has seen similar investment and bust around the world. Wind investment grew rapidly until the financial crisis, but when credit dried up, so did the profits of manufacturers.

With financial results anything but strong for most clean energy companies, it's easy to see why investors have pulled back on investments over the past year.

Clean energy is still big business Bloomberg points out that while investment may have declined year over year, 2012 was still the second-biggest year on record, with five times what was invested in 2004.

Lower costs may have also skewed the numbers lower in 2012. According to GTM Research, the cost to install utility-scale solar in the U.S. fell 30.4% in the third quarter of 2012 from a year earlier. First Solar, Inc. (NASDAQ:FSLR)'s low-cost modules and huge scale has helped drive that cost down to just $2.40 per watt.

Global installations were about flat in 2012, but with that kind of drop in price, it's easy to see how the dollars invested went down significantly. This cost reduction could be applied to both solar and wind -- lower investment doesn't necessarily mean lower installation.

Bright spots in 2012 Global investment in clean energy may have fallen 11% in 2012 but there were some bright spots in some major markets.

• China topped the list with $67.7 billion in investments in 2012, 20% higher than a year earlier. China is putting billions into its solar industry, so similar growth in 2013 should be easily attainable.
• South Africa came out of nowhere in 2012 to invest $5.5 billion, driven by wind and solar projects.
• Japan's clean energy investing picked up after the Fukushima disaster in 2011 and $16.3 billion was invested last year, up 75% from the year before. With heavy subsidies to the solar industry in the near term, we should continue to see strong numbers in 2013.

These markets are primed for long-term growth because they will be driven by economical clean energy investment (even after Japanese subsidies are reduced) and a need for more clean energy.

There are strong developments in clean energy in the U.S. Clean Energy Fuels Corp. (NASDAQ:CLNE) is building a natural gas fueling infrastructure that will make it viable for trucking fleets to transition to natural gas over the next few years. When it launches its new line of heavy-duty engines later this year the transition will really take hold. Electric vehicles from Tesla Motors Inc (NASDAQ:TSLA) have also proved that electricity can be a viable automotive fuel, at least for those who can afford it. But, even this investment wasn't enough to push the U.S. higher in 2012.