Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Details 1)

v2.4.1.9
Summary of Significant Accounting Policies (Details 1) (USD $)
Dec. 31, 2014
Dec. 31, 2013
Jun. 24, 2014
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities $ 0us-gaap_DerivativeLiabilitiesCurrent $ 6,277,000us-gaap_DerivativeLiabilitiesCurrent  
Fair Value, Inputs, Level 1 [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities   0us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
 
Fair Value, Inputs, Level 2 [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities   0us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
 
Fair Value, Inputs, Level 3 [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities   6,277,000us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
 
Convertible Notes Payable [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities   5,573,000us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= us-gaap_ConvertibleNotesPayableMember
 
Convertible Notes Payable [Member] | Fair Value, Inputs, Level 1 [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities   0us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= us-gaap_ConvertibleNotesPayableMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
 
Convertible Notes Payable [Member] | Fair Value, Inputs, Level 2 [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities   0us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= us-gaap_ConvertibleNotesPayableMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
 
Convertible Notes Payable [Member] | Fair Value, Inputs, Level 3 [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities   5,573,000us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= us-gaap_ConvertibleNotesPayableMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
 
Financing Warrant [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities   175,000us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_FinancingWarrantMember
1,733,000us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_FinancingWarrantMember
Financing Warrant [Member] | Fair Value, Inputs, Level 1 [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities   0us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_FinancingWarrantMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
 
Financing Warrant [Member] | Fair Value, Inputs, Level 2 [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities   0us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_FinancingWarrantMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
 
Financing Warrant [Member] | Fair Value, Inputs, Level 3 [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities   175,000us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_FinancingWarrantMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
 
Consulting Warrant [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities   529,000us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_ConsultingWarrantMember
4,019,000us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_ConsultingWarrantMember
Consulting Warrant [Member] | Fair Value, Inputs, Level 1 [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities   0us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_ConsultingWarrantMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
 
Consulting Warrant [Member] | Fair Value, Inputs, Level 2 [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities   0us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_ConsultingWarrantMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
 
Consulting Warrant [Member] | Fair Value, Inputs, Level 3 [Member]      
Summary Of Significant Accounting Policies [Line Items]      
Derivative Liabilities   $ 529,000us-gaap_DerivativeLiabilitiesCurrent
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_ConsultingWarrantMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member