The current single biggest telescope in the world is the Gran Telescopio observatory in the Canary Islands. It is a Keck type design and is 10.4M across (max edge diameter) which slightly exceeds the 10M diameter of Keck. You don't hear too much from this telescope however. Everything else is in the 8M class with the largest being the 8.4M primaries of the Large Binocular telescope in Arizona.
The new generation of big telescopes are intended to gather enough light to do spectroscopic analysis of exo planet atmospheres. These include:
Giant Magellan Telescope: 30 meter diameter using 7 mirrors of 8M diameter situated in Chile. This project is much further along than the others with most of the primaries already cast.
30 Meter Telescope: a Keck design telescope for Mauna Kea (on the site of the current 3.5M Canada-France telescope).
Exceedingly Large Telescope: 39M Keck type telescope situated in Chile.
Finally, there is the new 4M solar telescope on Haleakala which just started operation. It is intended to peer into individual convection cells of the sun's surface. In general, you get around 1000W/m2 of light so you have around 13,000W of sunlight being collected. This is dumped (via a deliberately low reflectance/high transmittance) coating on the secondary.
Giant Magellan Telescope
30 Meter Telescope
Extremely Large Telescope
Daniel K. Inouye Solar Telescope First Images
The new generation of big telescopes are intended to gather enough light to do spectroscopic analysis of exo planet atmospheres. These include:
Giant Magellan Telescope: 30 meter diameter using 7 mirrors of 8M diameter situated in Chile. This project is much further along than the others with most of the primaries already cast.
30 Meter Telescope: a Keck design telescope for Mauna Kea (on the site of the current 3.5M Canada-France telescope).
Exceedingly Large Telescope: 39M Keck type telescope situated in Chile.
Finally, there is the new 4M solar telescope on Haleakala which just started operation. It is intended to peer into individual convection cells of the sun's surface. In general, you get around 1000W/m2 of light so you have around 13,000W of sunlight being collected. This is dumped (via a deliberately low reflectance/high transmittance) coating on the secondary.
Giant Magellan Telescope
30 Meter Telescope
Extremely Large Telescope
Daniel K. Inouye Solar Telescope First Images